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Divisions of the Parietal Pome in Man
and Other Mammals.
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93
AUTHOR'S EDITION, extracted from BULLETIN
~ . ." of rife. . . : "..,\
American gºtuseum of 3%atural #istofº,
Vol. XIX, ARTICLE VIII, pp. 231–386.
AWeze, Yo?"/#, Yuly IZ, Z903.
– the Knickerbocher press, how work
xy
Article VIII.-DIVISIONS OF THE PARIETAL BONE
IN MAN AND OTHER MAMMALS.
By ALEŠ HRDL1éKA.
PLATEs VII-XXII AND 39 Text Figures.
CONTENTS. Ó "', a
( PAGE,
I. General Remarks... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
II. The Published Cases of Parietal Division in Man. . . . . . . . 234
a. Incomplete, Anomalous Parietal Divisions in the
Young. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
lb. Incomplete Parietal Divisions in Adults. . . . . . . 2.35
c. Complete Parietal Divisions....... . . . . . . . . . . . 236
III. The Published Cases of Parietal Division in Apes and
Monkeys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 242
Apes: Complete Parietal Divisions. . . . . . . . . . • * * * * 242
Apes: Incomplete Parietal Divisions. . . . . . . . . . . . . 249
Monkeys: Complete Parietal Divisions. . . . . . . . . . . 25o
Monkeys: Incomplete Parietal Divisions. . . . . . . . . . .252
Résumé of Published Cases of Parietal Division i
Apes and Monkeys. . . . . . . . . . . . . . . . . . . . . . . . . . 253
IV. New Material. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254
1. Cases in Man. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255
2. Partial Vertical (Infero-superior) Divisions in
Monkeys. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
3. Complete Vertical Parietal Divisions in Monkeys 271
4. Vertical-oblique Parietal Divisions in Monkeys. 273
5. Vertical Parietal Divisions with Extension into
the Temporal Squama, in Monkeys. . . . . . . . . . . . 276
6. Antero-posterior Parietal Divisions in Monkeys. 284
7a. Instances of Compound Incomplete Parietal
Divisions in Monkeys. . . . . . . . . . . . . . . . . . . . . . . ... 287
7b. Instances of Compound Complete Parieta
Diviſions in Monkeys. . . . . . . . . . . . . . . . . . . . . . . 295
V. Parietal Divisions in Mammals Lower than the Monkeys... 31.5
VI. Pathological and Accidental Parietal Divisions. . . . . . . . . . 3I 7
VII. The Causes of Anomalous Parietal Divisions. . . . . . . . . . . . 3I 9
Résumé as to Causation of Parietal Divisions in
Man. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 I
The Morphological Value of the Complete Antero-
posterior Parietal Divisions in Man. . . . . . . . . . . . 332
[231]
232 Bulletin American Museum of Natural History. [Vol. XIX,
PAGE -
The Morphological Value of the Very Oblique
Divisions and those that Run, between Two Con-
necting Borders of the Parietal in Man. . . . . . . . . 335
The Determining Causes of Parietal Divisions in
Man. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341
Critical Remarks Concerning Parietal Divisions in
Apes, Monkeys, and other Mammals. . . . . . . . . . . 343
General Conclusions. . . . . . . . . . . . . . . . . . . . . . . . . . . 347
VIII A. Partial Divisions of the Parietal Due to the Manner of
Ossification of the Bone. . . . . . . . . . . . . . . . . . . . . . 35o
VIII B. Wormian or Fontanel Bones in the Locations of the In-
complete Parietal Sutures and the Primary Parie-
tal Fissures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361
IX. Partial Divisions of the Parietal Bone Resulting from a
Mechanical Obstruction in the Ossifying Bone;
or Divisions to Foramina. . . . . . . . . . . . . . . . . . . . . 363
X. Bibliography and Alphabetical Index of Authors. . . . . . . . 382
I. GENERAL REMARKS.
The subject of divisions of the parietal bone was for the
first time brought to the attention of anatomists in 1753, when
Tarin, in his ‘Osteographie,” described a human skull, given
to him by Winslow, in which the left parietal bone was divided
into two by a horizontal suture. Since Tarin, observations on
parietal divisions have slowly multiplied until the present
time, and the literature of the subject has grown considerably
in bulk as well as importance. The authors to whom we are
particularly indebted for casuistic material or scientific re-
search in this field are W. Gruber, Welcker, Hyrtl, Toldt, and
Ranke; besides these authors, however, there are others who
have made especially valuable reports of individual cases or
contributed more or less to the elucidation of the problems
arising from the observations, such as Soemmering, Calori,
Putnam, Turner, Dorsey, Fusari, Coraini, and others.
With increase in the number of observations of parietal
divisions the subject extended to all stages of life in man, from
adults to foetuses and embryos. Eventually the anomaly
was also found in apes and certain monkeys; no case, how-
ever, has thus far been signalled in any lower mammals than
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 233
monkeys. There are on record, considering only the com-
plete antero-posterior divisions, 9 such cases in human em-
bryos, foetuses, and children, and 18 in human adolescents
and adults; and of different complete divisions 2 instances
in apes and 4 in monkeys.
As the material augmented there became apparent an in-
creasing diversity in the nature of the parietal divisions. In
Tarin's case the anomalous suture was complete and ran be-
tween the anterior and posterior borders of the bone in a
nearly horizontal direction, or nearly parallel with the sagittal
suture. A number of sutures of the same class was reported
subsequently; but there appeared also records of divisions
running obliquely between the anterior and posterior borders;
obliquely between the posterior and inferior borders; and
vertically between the superior and inferior borders of the
parietal. In addition there were described in the course of
time a few angular sutures, which look like combinations of
vertical and horizontal, or vertical and oblique divisions. A
certain amount of attention was further given to incomplete
sutures and the foeta1, apparently normal, fissures in the
parietal.
While the observations on divisions of the parietal bone
multiplied, no serious efforts to explain the anomaly were
made before the latter part of the 19th century. Soemmering,
in 1826, recognized the congenital nature of the divisions, but
expressed no theory as to their causation. Welcker, in 1862,
was of the opinion that where the parietal bone is divided into
two large portions, these portions are of a different nature
from simple intercalated bones (bibl. note 17*; p. Io9); but
in 1892 (55), notwithstanding the already known work of
Toldt, Welcker * denies the possibility of the two portions of
a divided parietal developing from two centers. For Calori
(1867, bibl. note 20; p. 341) the division of the parietals was
the result of a separation and independent growth of a portion
of the center of ossification of each bone, the separation being
due to the mechanical effects and nutritive disturbance
* The number 17 refers to a bibliographical note at the end of the paper.
*Abnorme, Schädelnähte, p. 21: “Von einer Entwickelung der beider Hälften des
getheilten Scheitelbeinen aus zwei “ Kernen' kann wohl nicht die Rede sein.”
*34 Bulletin American Museum of Natural History. [Vol. XIX,
1-tº-
caused by hydrocephalus. Hyrtl, in 1871 (23), misled by the
occasional close relation of a horizontal or oblique parietal
Suture with the temporal ridge, was inclined to connect this
latter with the causation of the suture. Toldt (1882–83;
48, 49) and Ranke (1899; 36) have undertaken new re-
Searches into the development of the parietal bone, and the
result of these was a conclusion, arrived at by both the
authors, that the parietal bone does not develop from one
focus, as has been taught, but from two distinct centers of
Ossification, which ordinarily fuse early and form one, but
Occasionally remain separate and then give rise to a double
parietal. Since Toldt's publication the theory that a double
parietal center is the original cause of the complete antero-
posterior parietal divisions has gained adherents in Putnam,
Turner, Coraini, and others.
In 1896–97 Maggi, of Pavia (59, 60), announced, basing
his conclusions on his own observations on human foetuses,
that the parietal bone develops from three centers, two of
which, however, soon coalesce. In a few cases he noticed as
Imany as four centers in the parietal. For all instances of
Imultiple foci of Ossification we find, according to Maggi,
homologies among the stegocephali, batrachians, and in
Dicynodon.
Finally, most recently (1900; 70) Frassetto, another Italian
author, basing his views on some of the observations of Maggi
and some old as well as new clinical material, advances the
theory that the human and primate parietal develops regu-
larly from four centers of ossification.
The active cause, or causes, which in the exceptional cases
prevents the parietal centers from fusing and allows them
to develop into two or more separate bones, has been
touched upon only by Calori (l.c.) and more recently (1894)
by Coraini (33), to whose views we shall return later.
II. THE PUBLISHED CASEs of PARIETAL DIVISION IN MAN.
Before proceeding with the series of new observations, or
with individual critical considerations on the subject of parie-
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 235
tal divisions, it is essential to review with some detail the
material that has already been published. In order to facili-
tate the task, I have collected and arranged the records in the
following groups and tables. The partial and complete ANoMA-
Lous divisions of the human parietal bone will alone be here
considered; parietal fissures in foetal and infant bones will
be treated of in a special chapter.
(a) Incomplete, Anomalous Parietal Divisions in the Young.
Hyrtl, in 1871 (23), reported, besides his other cases, one of
a posteriorly incomplete division in the left parietal bone of a
female foetus before term. The division runs from a deep
cleft in the middle of the anterior border of the parieta1, with
a slightly curved course over the eminence, ending half an
inch in front of the 1ambdoid suture.
Ranke (36) reports numerous instances of posterior and a
few of anterior parietal fissures on the skulls of 8–Io-months-
old foetuses and infants; but most, if not all, of these cases
loelong in the category of normal divisions. The same may be
said of the observations of Albinus, Gerdy, Welcker, Hamy,
Augier, and Debierre (38–47).
(b) Incomplete Parietal Divisions in Adults.
Cases of this nature were reported principally by Lobstein,
Broca, Welcker, Coraini, and Ranke.
In Lobstein's case (Io), the left parietal of a 38-year-old
white male showed a vertical division, which began in the
temporal squama and ascended towards the parietal eminence.
Total length of the suture, 2 inches 9 lines (7.0 cm.). No
signs of any injury.
In Broca's case (38), a partial vertical suture passed into
each parietal from about the point at which is located in early
life the sagittal fontahel. (Allied cases are mentioned by
Barkow (39), Otto (40) in Tiedemann’s ‘Zeitschr. f. Physiol.’
(41), and by Pozzi (42).
Coraini reported a case (33) where the right parietal
of a 29-year-old white male showed a superiorly incomplete
236 Bulletin American Museum of AWatural History. [Vol. XIX,
vertical division, allied somewhat in location and course to the
complete vertical suture reported by Fusari (vide table of
complete divisions).
Welcker describes briefly (55, p. 21, pl. ii, fig. 16) a
case in a 50-year-old male native of New Hebrides. The
skull shows on right a 1.6-, On left a 3.o-cm.-long, fairly ser–
rated, horizontal suture running into each parietal from near
the middle of its occipital border. Another skull (pl. ii, fig,
I 5) shows on each side a similar, 2.1-cm.-long division run-
ning forward from the middle of the lambdoid suture.
Ranke reported (36) three observations belonging to this
category of cases. In one specimen the right parietal bone
showed a 6.3-cm.-long horizontal suture in about the middle
of its posterior portion. In the second case a similar pecu-
1iarity existed on both sides. The divisions started in about
the middle of the posterior border of each parietal; it was
2.0 cm. long on the right, 1.5 cm. on the left side. The third
skull showed a 5.8-cm.-long remnant of a horizontal suture
running from the middle of its posterior border into the right
parietal. All the three crania belonged to the old Bavarian
population.
Total of incomplete parietal divisions (individual) in the
young and adults (including only Broca's case of the Sagittal
vertical ones), I 3 ; of which 4 horizontal were in the anterior
and 5 horizontal ones in the posterior portion, 2 vertical in
the superior and 2 vertical Ones in the inferior portion of the
parietal. - * *
(c) Complete Parietal Divisions. ſº
In order to present these cases with more advantage, I
have arranged them into the annexed tables A and B.
Besides all the above there are in literature descriptions
or mention of cases which cannot well be classified, or whose
nature is doubtful. Due to the scarcity of the publications
referred to, I was able to examine directly only Jung's and
Gruber's communications.
Young.—Jung, C. G. (9), published in 1827 an observation
on the skull of a new-born male child, which showed, besides
an extreme number of Wormian bones, irregular divisions in
TABLES OF RECORDED COMPLETE DIVISIONS OF THE PARIETAL BONE IN MAN.
TABLE A. CASEs IN FOETUSEs AND THE VERY YOUNG.
I. Antero-posterior Complete Divisions, Parallel, or nearly so, with the Sagittal or Squamous Sutures.

Author, iff * Miscellaneous.
year of report, Race of A Parietal Location of Division; Diſ º 111 *
No. referring to subject. Sex. ge. divided. the anomalous suture runs: size of t à Asym- e Inter-
bibliography. two parietals. metry. | Pathological. |, calated
bones, etc.
Van Doeveren white P P left nearly across the middle of the pari- P P P P
1765. (4). ‘‘child.” etal; exact terminations not stated
Murray, A. white male foetus. both lexact terminations f P P hydrocephalus P
1797. (5).
Pandolfini & white P foetus both lexact terminations 2 P P P 7
Ragnotti
1898. (58)
Total 3 cases, all whites |1 male, I in a I left, Exact direction and terminations in P P 2 * P
2 sex un- || “child,” 2 both all uncertain one hydro-
known, |2 in a foetus (of 6 parie- cephalus
tals 5
divided)
II. Antero-posterior Complete Divisions, Moderately to Markedly Oblique.
Calori, L. white P foetus right P P P hydrocephalus P
1840. (12). (one-eyed)
Gruber, W. white male | 9 mo. foetus left the upper part of the parietal is P P cerebral her. P
1852. (I 3). (with super- higher anteriorly, the lower part nia through
numerary posteriorly the occi-
digits) pital fon-
tanel ; de-
fect in hard
palate.
Ramsay, H. white P 8–9 mo. foetus right from sphenoidal angle to middle of the divided pai skull “split palate” in lamb-
Traguair occipital border rietal larger by asym-- doid and
1863. (18.) * 4. than the un- metrical coronal
divided one Sutures
Hyrtl, J. white female || 5 mo. embryo 1eft from near bregma, on the anterior, to P P P P
1871. (23.) just above asterion, on the pos-
terior border
do. white P 4 mo. embryo right |from above the middle of the anterior P P P P
187 I. (23.) border to asterion
do. white P 6 mo. embryo. right |from lower portion of anterior border P ? P P
1871. (23.) backward and upward to the emi-
nence and then backward and
downward to below the middle of
the posterior border
Bianchi, S. white ? 3% mo. embryo left the superior portion of the divided P P P interpari-
1893. (31.) (traces on parietal is higher anteriorly but etal and
right lower posteriorly than the inferior preinter-
portion parietal
bones
Total 7 cases all whites | I male I—3% mo. right and In 4 the division runs obliquely back- |In I case the In I skull |In I hydro-|In 2:
1 female 1–4 “ 8. right ward and upward, divided pari- asym- cephalus, in 5 f
5 r—5 “ traces) in 2 it runs obliquely backward and etal con- metrical, in 2 defect in
1—6 “ 3 left downward, siderably in 6 hard palate,
2 near or at (of 14 in I ? larger, in I cerebral
term parietals in 6 2 hernia,
I f 7 divided in 4 f
and on 1
traces of
division)
III. Oblique Divisions Terminating in the Posterior and Inferior Borders of the Parietal.

Pandolfini &
Ragnotti
1898. (58);
ter Fras-
SettO
white
foetus
(age 7)
both
bilateral separation of posterior-in-
ferior angle of the parietal
TABLE B. CASEs IN ADolescents AND ADULTS.
I. Antero-posterior Complete Divisions, Parallel, or nearly so, with the Sagittal or Squamous Sutures.
Author,
year of report,
No. referring to
bibliography.
Race of
subject.
Sex.
Age.
Parietal
divided.
Location of Division;
the anomalous suture runs:
Difference in
size of the
two parietals.
Miscellaneous.

Asym-
metry
Pathological.
Inter-
calated
bones, etc.
Tarin, Win-
slow
1753. (I.)
Soemmering,
1826 (8.)
Welcker, H.
1862. (17.)
Deslong-
champs,
1864-'5. (10.)
Hyrtl, J.
1871. (23.)
Zoja, G.
1874. (53.)
Putnam, F. W.
1883. (26.)
Turner, W.
1884. (27.)
Turner,
W.
1891. (29.)
Welcker, H.
1892. (55.)
Curnow, J.
1893. (30.)
Zoia, G.
1895. (53.)
Dorsey, G. A.
1897. (34.)
Ranke, J.
1899. (36.)
Pitzorno, M.
White
white
white
New Cale-
donian
White
white
prehistoric
race 111
Tennessee
native of
Admiralt
y
Islands
native
Australian
White
(Prague)
white
(München)
white
(Berlin)
( Lº:
ubinger
skull)
white
white
Maori
white
white
male
male
male
male
female
male
male
male
male
male
male
male
male
male
adult
30-50 y.
18–20 y.
abt. 20 y.
18 y.
i young adult
adult
adult
adult
25 y.
50 y.
adult
adult
left
both
left
left
left
right
left
right
(traces on
left)
right
right
right
left
right
left
right
left
right
(remnant
on left)
left
below middle, nearly parallel with
the Sagittal suture, posterior ter-
mination somewhat higher than
the anterior
nearly along the middle of each bone
below the middle
nearly along the middle of the pari-
etal
between the middle and lower thirds
of the bone
slightly above the inferior third of
the parietal; terminates somewhat
higher above asterion than above
pterion
slightly above the inferior third of
the parietal
somewhat below the middle
somewhat below the middle
runs from slightly above the middle
of the lambdoid to slightly below
the middle of the coronal
nearly along the middle; posterior
termination slightly higher than
... the anterior
nearly along the middle, terminating
somewhat higher posteriorly than
anteriorly
Between the middle and inferior
thirds of the bone (the anteriorly
remaining portion of the division on
left runs between the fourth and
inferior fifths of the bone)
divided bone
considerably
igher than
that of the
opposite side
divided bone
higher than the
undivided one
divided bone
higher and
811
more bulging
than the
undivided one
divided bone
igher
divided bone
higher
divided bone
larger in all
dimensions
divided bone
higher than
the undi-
vided one
divided bone
on right
slightly higher
than the
parietal of the
opposite side
P
skull
slightly
3.SVIQ-
metrical
skull
asym-
metrical
Skull Some-
What
asym-
metrical
P
skull
asym-
metrical
(due partly
to artificial
deforma-
tion)
occipital
region
asym-
metrical
slight
somewhat
asym-
metrical
skull
slightly
asym-
metrical
(Occipital re-
gion shows
considerable
artificial
flattening).
A few small
ones in
lambdoid
sut. .
Metopic
Suture.
Mºric
mastoid
Sutures.
Wormian
bones in
middle of
left coronal,
angl.
lambdoid,
and one in
the right
lambdoid
suture.
Metopic.
suture.
P
A small
Wormian
at lambda-
For. mag-
#ºr
angu º
very large.
13 inter-
calated
bones,
moderate
to large
size, in the
lambdoid,
two in the
anomalous
suture, and
several in
the tem-
poro-pari-
etal articu-
lation on
right
One inter-
calated
bone in the
anomalous,
Several in
lambdoid
Suture.
A small
Wormian
in left
asterion.
Metopic
Suture.
P
A small
Wormian
in the
beginning
of the
anomalous
Suture
posteriorly
An
occipital
“apex.’
bone.
f
One small
Wormian
in and one
below the
anomalous,
and several
small ones
in other
Sutures.
A few small
Wormians
in the
lambdoid
suture

(after Frasset
to, IQoo
( 54
Turner, W.
1902. ( ..)
white
male
adult
left
runs nearly between the lowest and
the upper two thirds of the parietal
Total 19 cases
14 whites
I New-Cal-
edonian
I Ameri-
can Indian
I Admi-
ralty-
Islander
I Aus-
tralian
I Maori
14 males!
1 female
4 *
3 adolescents
13 adults
3 *
I both
Io left
2 right,
with traces
on left
6 right
(of 38
parietals
20 divided
and 2 with
traces of
division)
Along or nearly along the
middle of the parietal. .5 cases
(6 parietals)
below the middle..... 4 ( 9 cases
between the middle º
and lower thirds.... 5 ( (9 parietals)
exact location doubtful in º
5 CaSeS . . . . . . . . . . . . . . (5 parietals)
In 8 cases the
divided pari-
etal higher
than the
undivided one;
Io P
In 1 case,
where both
parietals were
completely
divided, the
bones Were
nearly equal
III Ore OI’
less
asymmetry
in 8;
II P
No patho-
logical con-
dition re-
ported in 9;
Io P
Metopic
Suture
persistent
in 4;
mastoid su-
tures per-
sistent in
one to
Imany 1m-
tercalated
bones in
ordinary
suturesin 9;
none 1n I ;
P 8.
Inter-
calated
bones in
the
anomalous
Suture in 4.
TABLE B. II. Antero-posterior Complete Divisions, Moderately to Markedly Oblique.
Author, Diff - Miscellaneous.
ear of report, Race of & Parietal Location of Division; 1ſterence 1n
{. ºte; tº subject. Sex. Age divided. the anomalous suture runs: size of i. A - Inter-
bibliography. tWO parietals. SYin" | Pathological. calated
metry. bones, etc.
Lucae, J. C. G. White P young adult right |from the lower end of the coronal to divided bone skull asym- P The illus-
1857. (I6.) slightly above the middle of the considerably metrical tration
lambdoid suture larger than the shows a
undivided one small
Wormian
bone in the
Sagittal,
and one or
two small
ones in the
lambdoid
Suture
Calori, L. white female 37 y. lboth on right: from a point 2.2 cm. above not much skull some- * Inter-
1867. (20.) asterion to 1.5 cm. from bregma; difference what asym- calated
on left: from near lambda to a point metrical bones at
4.6 cm. below bregma both ends
of the left
anomalous
Suture, and
in both
pterions;
mastoid su-
tures per-
sistent
Gruber, W. white probably adult right |from a point 1.9 cm. above the the divided skull some- gºmº. No
1879. (25 ) female parieto-sphenoidal suture, to , a], parietal is, what asym- Wormian
point 4.0 cm, above the parieto-|higher than the metrical bones men-
mastoidal suture, 5.o cm, below undivided one tioned or
the lambda. visible on
illustra-
tion
m. F. W. prehistoric male adult left, left; from a cleft at a point 2.3 cm. left parietal skull 4- A large
Pº y (26.) | ...race in (45–55 y.) (on right aſ above asterion; descends towards higher than slightly (Occiput wºn
Tennessee separation the anterior 3 of the squamous the right asym- moderately bone in the
of pos- suture, then obliterated, but trace- metrical compressed) | cleft from
terior- able to a point 2.0 cm. above the which
inferior lower end of the coronal suture. starts the
portion) (right: the separate portion measures left anom-
2.0 cm, along the lambdoid, 3.5 cm. alous Su-
along the parieto-mastoid, 3.9 cm. ture; a
along the squamous suture, and 4.5 small
cm. in a straight line from its su- Wormian
perior lambdoid to its anterior ter- in right
mination) lambdoid
suture
, Per-
sistence of
1metopic su-
ture
white male adult right from a point Ҽ inch above the ar- ? P
Bºstºy ticulation with the lateral angle of P P
the Occipital” (asterion) obliquely
forward and upward, to within
“an inch from the anterior border,
slightly above the middle.”
Smith Egyptian P P P “from the lambda to the pterion” P skull asym- P P
Barclay, metrical
1899. (35.)
tº tº white female aged both the left anomalous suture runs from P P OneS Ver
Tºº { 71.) lambda to slightly above the middle #. tº. º #:
of the coronal; the right from a other skeletailbone at the
little below lambda to slightly above abnormalities base of the
the middle of corona ief; anom.
alous in
lambdoid
Suture
Total 7 cases 5 in whites|| 2 males 5 adults 3 right In 7 the suture ran backward and In 3 the com- In 5 skull |In 3 - In one case
I in an 2 females | 1 probably 2 both upward (terminating, higher pos- pletely di- § to 3 f ... a per-
American I probably adult I left teriorly than anteriorly), vided bone was markedly In I advanced sistence of
Indian female I ? ... in 2 it ran backward and downward higher than asymmet- changes in all |metopic, in
I in an 2 : (of 14 pari- (terminating higher anteriorly) that of the rical, the bones; another
Egyptian etals 9 di- opposite side in 2 f other skeletal case
vided) 3 f abnormalities mastoidal
In I case, sutures
where both Inter-
parietals were calated
completely bones at
divided, the one of the
bones were ends of the
nearly equal anomalous
jºure 1Il 3
2

© e > *
e ‘P e
e e e
tº e º 'º
©
TABLE B. III. Oblique Divisions Terminating in the Posterior and Inferior Borders of the Parietal.

Author, - º Miscellaneous.
year of report, Race of * Parietal Location of Division; Piº 1Il
No. referring to subject. Sex. Age. divided. the anomalous suture runs: size of t i As Inter-
bibliography. two parietals. ... | Pathological. [...calated
metry. OneS, etc.
Ekmark, C. D. white * 45 y. p ? separates the mastoid angle of the P P hydro- P
1763. .(3.) bone cephalus
(Ascribed by
Calori, to
Aurivillius)
Welcker, H. Whites ? P P “several skulls,” where a suture runs ? P P f
1862. (17.) from the middle of the margo-
lambdoideus to the inferior border
of the bone
Hyrtl, J. Gypsy male abt. 20 v. right | “from the point of the occipital | divided pari- |skull sym- -*. A Wormian
3. (23.) y squama (lambda) to the middle of letal somewhat metrical bone in
the squamous suture” longer than lambda
that of the
opposite side
Gruber, W. White male abt. 30 y. both on; no details as to the termina- P f (Occipital Wormian
. ( 25. 1OnS; flatteni bones
1879. (25.) on 1eft: from “the middle of the su- attening) nº.
perior border of the temporal locations;
squama, 4.5 cm, posteriorly to the an epactal
wing of the sphenoid, to a point bone
2.5 cm. from the posterior ex-
tremity of the sagittal suture.
Gruber, W. White male advanced age left on left: “from the middle of the P P f f
1879. (25.) (all sutures (traces on lambdoid” “to the middle of the
patent, right) parieto-temporal suture; ”
hence leSS (on right: from a point below the
than 50 y.) upper § of the lambdoid suture,
forward and downward; incom-
plete inferiorly)
Welcker, H. white female 7o left |from slightly above the middle of the P P P P
1892. (ss.) y lambdoid to nearly the middle of
the temporo-parietal suture
Coraini, E. white P adult f from middle of squamous to lamb- f P smººse f
1894. (33.) doid suture
Ranke, J. white P adult left from upper portion of the lambdoid P ? sº Two
1877 & 1899. to near the middle of the squamous “spitz.”
(36.) suture tones in
lambda
do. white P adult right |on right: a 6.5 cm. long suture, sepa- P P gº- Metopic
do. (36.) (left in- rating the mastoid angle; suture
complete)|(on left: a 2.9 cm. long suture, in Wormian
same location, incomplete inferi- bones in
orly) lambdoid
suture
do. white P adult right |from a point a little inferior to lambda P P 2 f
do. (36.) towards anterior part of the
squamous suture, reaching to with-
in 2.6 cm. of the same.
Total of cases I in a 3 in males, I adolescent, 3 right the posterior termination is not re-| In 1 case the In r skull In 1 hydro- Metopic
(including Gypsy, 1 in a fe- the remain- 3 left stricted to any part of the occipital | divided pari-, symmetri-| cephalus suture in 1
Putnam's de- the remain-male, in the ing probably ... I both border of the parietal; it occurs|etal is reported cal; in the 4 ~ 2 Wormian
scribed un- 1ng 1n remaining all adults the others?] below, at, and also above the mid- to have been remaining the remain- bones in 3
der II) whites Sex P (of the 18 |... dle of the border; longer than the ing f Epactal
- II - I 2 parietals, the inferior termination most fre- .#. One . bone in 1
not in- quently takes place at, or not far in , the re- “Point”
cluding from, the middle of the tempero-|maining cases f bones (in
Welcker’s parietal articulation. lambda)
I 862 in I
&Putnam’s In the
Cases, I 2 tº ſº
with divi- remaining f
sions)
TABLE B. IV. Vertical-horizontal and Vertical, Complete, Divisions.
Gruber, W. White P adult left a vertical horizontal suture, sepa- f P P f
1852, (14.) rating a 2% inches high and Ił *
inches broad piece of the posterior-
inferior part of the parietal
do. white male adult right separation of the posterior-inferior ? P P ?
1876. (24.) portion by a slightly curved hori-
zontal-vertical suture; antero- pos-
terior branch of the suture begins
4.2 cm. above asterion, the vertical
branch ending in the middle of the
SQuamous Suture,
Fusari, R. white male 23 y. right a complete vertical suture from the P f f f
1889. (28.) Superior to the inferior border of
the parietal, near its posterior
(Reported third; and a horizontal division
again in 1897 Between the lambdoid and an-
by G. Mondio omalous sutures, well above their
57) middle
Total 3 cases all whites 2 gales all adults 2 right | In 2 ºp. toy a vertical–hori- f f f f
I f 1 left . zontal suture of the posterior-in-
(of 6 pari- || ferior portion of the parietal
etals, 3 |in 1 a complete vertical division with
with a transverse division of the pos-
divisions) terior separate portion

1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 237
both parietals. The right bone was separated into 5, the left
into 3 portions.
Gorgone's case (II): According to Coraini’s citation (33)
it seems that Gorgone has observed a vertical division of a
parietal bone in a foetus (“essendo sempre più rara 1a division
verticale osservata da Soemmering (?) e da me una sola volta
redutta . . . in parietale però di feto”).
Hartmann's case(50): Ranke mentions (36, p. 33) this case
as one that possibly belongs among the lambdoid-squamous
parietal divisions.
A cranium of a new-born child, with a parietal suture, has
also been reported, according to Ranke (36, p. 58), in Rūd-
inger's catalogue of the skulls and skeletons in the Munich
Anatomical Institute. -
Adults.-The first of these cases is that of Sue (2), referred
to by Calori and Coraini. According to a citation by Calori
(20, p. 34o, footnote), the specimen showed either a separa-
tion of a portion of the postero-superior angle of the left
parietal, or a large Wormian bone in that location (“J'ai vu
un pariétal gauche dont le quart de la partie postérieure et
supérieure n'est qu'un os wormiens dont la largeur excedoit
un travers de doigt'’).
Blumenbach’s case (7): This observation is mentioned by
Welcker, who says the illustration of the specimen can be seen
in Blumenbach’s “ Nova Pentas,’ LXI. According to Welcker
there is seen, on a skull of an old German, “a transverse suture
of the right parietal bone, running from the middle of the
temporal to the sagittal border, parallel in whole to the coronal
suture.” -
Gruber's case (22): The right parietal of the skull of a 15–
18-year-old white male showed an oblique, partly occluded
division, and this was continuous with a division in the occip-
ital squama. The illustration of the division shows none of
the distinctive characters of a suture. Both Hyrtl and
Ranke exclude this case from the category of anomalous
parietal sutures.
Gruber's Prague Museum case: A mention is made of this
case by Gruber (22). The author expresses the belief that
238 Bulletin American Museum of Natural History. [Vol. XIX,
one of the skulls he has seen in the Prague Museum showed an
antero-posterior division of one of its parietals. It is prob-
able that this is the same case later on (1892, 55) referred to
by Welcker and given in Table B, I.
Finally there is the case of a Fidji-Islander, No. 50 in the
Rabl–Rüchard's Katalogue of the Berlin collection. Welcker
is of the opinion (55) that this case, referred to in the
Katalogue as one presenting on the left side a Wormian bone
that extends between the parietal and temporal bones from
the coronal to the lambdoid suture, is only another instance
of a complete horizontal parietal suture.
RÉSUMá.—Leaving the incomplete and doubtful cases aside,
the above records comprise 51 to 52 cases with in all 58 to
59 anomalous parietal sutures running completely from one
to another border of the parietal bone.
Age.—II of the cases here considered were observed in em-
bryos, foetuses and a “child,” 4o to 41 in adolescents and
adults.
Race.—If in all the cases where the race of the subject has
not been reported we assume that the subject was a white,
there were then among the young all whites, among the ado-
lescents and adults 43 to 44 (84 to 86 %) of whites and 8
(bet. I6 and 14 %) individuals of other races.
The absence of representatives of other races among the
young is probably entirely due to the comparative scarcity of
naterial from those races.
Of the individuals of other races than the white among the
adults, there were
2 ancient Americans (Tennessee), I from the Admiralty Islands,
I gypsy, I New Caledonian, and
I “Egyptian,” I Australian.
I Maori,
t
Sex,−Among the 29 cases in which the sex was reported 23
are males, 5 females, and I “probably” female. The males
preponderate over the females in the ratio of nearly 5 to I.
Side.—The anomalous divisions where their location was
mentioned, were:
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 239
In the young: 4 right, 3 left, 3 bilateral, I left, with traces on right.
In adolescents and adults: 14 right, 15 left, 5 bilateral, 2 right,
with traces on left.
Total, 18 right, 18 left, 8 both sides, 2 right and I left with traces
on the opposite side.
Location.—In 41 instances the suture extended horizontally
or obliquely between the anterior and posterior, in 16 to 17
between the inferior and posterior, and in I between the in-
ferior and superior border of the parietal.
Among the young in 3 of the cases (27 %), or 5 instances,
the divisions were probably horizontal (parallel with the
Sagittal suture); in 7 cases, or the same number of instances,
(63.5%), oblique; and in one case, or two parietals (9 %)
oblique infero-posterior. Among the adolescents and adults
the division was in 19 of the cases, or 20 instances (52.6 %),
horizontal; in 7 cases, or 9 instances (18.4 %), oblique antero-
posterior; in II to I2 cases (28.9%), oblique infero-posterior; in
2 cases (5.3%), angular infero-posterior; and in I case (2.6%)
vertical, or infero-superior, with a partial horizontal ramus.
Of the 25 horizontal divisions all, so far as reported,
ran at or below (the majority) the middle of the parietal
lbone. Of the I6 antero-posterior oblique divisions, 4 in the
young and 7 in the adults ran in a backward and upward, 2 in
the young and 2 in adults in a backward and downward di-
rection from the anterior border of the parietal: in one in-
stance the exact course of the division is uncertain.
Size of the parietals.-The divided parietal bone is generally
larger than the undivided one in the same skull; the excess in
size is mainly at, or nearly at, a right angle to the anomalous
Suture.
Asymmetry.—Unless both parietals are completely and
similarly divided, more or less asymmetry of the skull is
probably the rule. This asymmetry is principally due to the
unequal growth of the two parietals.
Pathological.—Of the fatal skulls every one in which we
have a report on this point, showed some pathological or
teratological features. There were in four specimens two
hydrocephali, two defects in the hard palate, an abnormally
:
24O Bulletin American Museum of AWatural History. [Vol. XIX,
:
:
:
:
:
e
i.
- - -, *r -
large posterior fontanel with a cerebral hernia, one instance
of monoculism, and one of polydactyly. One case of a hy-
drocephalus is reported among the adolescents and adults.
Intercalated Bones.—One to a considerable number of such
bones of various sizes were present in a large majority of the
cases. In 7 instances there was one or more Wormian bones
present at the beginning or in the course of the anomalous
Suture.
Persistence of Early Normal Sutures.—The persistence of
the metopic or frontal suture is reported in 6, mastoid sutures
in 2, transverse occipital in I of the adults.
Characteristics of the Anomalous Sutures.—The antero-pos-
terior horizontal or moderately oblique parietal sutures in
adults are generally well serrated in their middle or their
middle and posterior thirds; anteriorly, however, these divi-
sions are often of a more or less squamous character, the bor-
der of the inferior overlapping that of the superior portion
(cases of Lucae, Hyrtl—20-year male, Gruber—“probably fe-
male,” Putnam, Ranke). The infero-posterior divisions show
on the average a less pronounced serration than the antero-
posterior ones; occurrence of squamous character is uncertain.
The relative persistence of the anomalous divisions seems
occasionally to equal that of the majority of the normal parie-
tal articulations, or even to slightly exceed the same. In
Soemmering's, one of Hyrtl’s and Ranke's cases, the anoma-
lous sutures were still externally patent, while some of the
normal parietal articulations showed traces of occlusion. In
Dorsey's case the anomalous division was patent externally,
but occluded ventrally, and there was a partial synostosis in
the sagittal suture. On the other hand, some of the partial
divisions in adults seem to point to an occasional early occlu-
sion of the supernumerary suture. -
The preceding data make it evident that divisions of the
human parietal bone may be encountered at all ages from
the embryonic to advanced adult life. The process of suture
obliteration may somewhat interfere with the detection of
such divisions in the aged.
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 241
Considering the relative supply of material, it seems that
the divisions occur more commonly in the colored races than
in the whites; this point, however, cannot be decided before
there are opportunities of examining very much larger num-
ſhers of crania belonging to the various colored races than has
teen possible up to the present time. The anomaly is cer-
tainly exceedingly rare in both prehistoric and more recent
native Americans.
A very striking feature is the predominance of parietal divi-
sions in males. The proportion of 5 males to I female might
possibly be slightly altered if we had reliable records as to the
sex of the subject in all the cases.
Parietal divisions in man are more often uni- than bi-lateral
(in about the proportion of 5 to I). The unilateral divisions
occur with about equal frequency on the two sides; appar-
ently there is no cause in man which would influence the phe-
nomenon to appear more frequently on one side than on the
other.
According to their terminations and direction, the anoma-
1ous parietal sutures can be, as has been done in the tables,
arranged into several classes. The antero-posterior divisions
predominate over the infero-posterior ones, but this may be
due to the fact that the former, through their more strik-
ing character, have received greater attention (v. Ranke, 36,
p. 33). The vertical or infero-superior sutures are appar-
ently exceedingly rare.
Of the antero-posterior divisions, the oblique are some-
what more common than horizontal ones in the young, while
in adolescents and adults the condition is reversed, the ob-
lique sutures being in a decided minority. It is not improb-
able that some divisions, originally oblique, do gradually, as
the bones grow, assume a more horizontal direction.
The fact of the existence in the four skulls of foetuses
at or near term, in which a parietal division was observed,
of pathological or teratological abnormalities, can hardly be
without a special significance. We shall return to this point
in the concluding chapter. There cannot, however, before
we possess additional data, be much meaning attached to the
[% une, 1903.] 16
242 Bulletin American Museum of Matural History. [Vol. XIX,
frequent presence of intercalated bones in crania with a pari-
etal division, or to the occasional persistence in such speci-
mens of the metopic or mastoid sutures. In some reports
these features are not touched upon, in consequence of which
the figures cannot well be reduced to percentages and used for
comparison with observations on similar conditions in crania
which do not present a division of the parietal. The occur-
rence of Wormian and even fontanel bones in crania in which
the parietal bones are normal is very common, nor is it rare to
find in such specimens, as is well known, a complete metopic
or a more or less preserved mastoid suture.
III. THE PUBLISHED CASEs of PARIETAL DIVISION IN APEs
AND MONKEYs.
The data and remarks in the preceding chapter cover
briefly the accumulated published material on parietal divi-
sions in man. In addition we have in literature a smaller
number of observations, by Gruber, Coraini, Maggi, Ranke,
Imyself, and Frassetto, on similar anomalies of the parietal
bone in the apes and monkeys. These observations, which
by their nature add much additional interest to the whole
matter of parietal divisions, are as follows:
APES : COMPLETE PARIETAL DIVISIONS.
Ranke's Case: Complete Division of a Parietal Bone in an
Orang.”— Among the 245 orang skulls of the Selenka's collec-
tion in the München Anthropological Institute, Ranke found
one in which the right parietal bone is divided into a larger
upper and a smaller lower portion by a horizontal suture.
The skull is that of an adolescent female. The abnormal
suture “runs nearly parallel with the sagittal suture”; but
its posterior end bends downward and ends on the inferior
border of the bone, near the junction of the squamous with
the lambdoid suture. The abnormal suture shows but little
Serration and is squamous in character, the lower overlapping
the upper portion of the bone. The height of the superior is
*L. c., p. 3ro.
1903.] Hrdliča, Parietal Bone in Man and Other Mammals. 243
to that of the inferior portion, at the anterior border of the
parietal, as 3 to I (6.0 and 2.0 cm.). The lower portion pro-
jects further forward than the upper.
Frassetto's Case (69). — The right parietal of a well-formed,
slightly asymmetrical skull of an orang (adolescent) shows
Fig. 1. An Orang, showing a complete antero-posterior parietal division. (After Ranke.)
an oblique, complete division, beginning o.7 cm. below the
lambda and ending in the coronal below its middle. The pos-
terior half of the anomalous suture is well serrated, the an-
terior half simple. A moderate-size Wormian (more properly
fontanel) bone is seen in the posterior end of the suture.
The right parietal bone is slightly larger than the left. (The
division here described is strikingly similar to those reported
in a human subject by Terry, Table B, II.)
My Case in a Chimpanzee (37). — A bilateral complete divi-

244 Bulletin American Museum of Matural History. [Vol. XIX,
Sion of the parietal bones in the skull of a 9-year-old male
chimpanzee (“Chico’).
“The skull shows in general a good development and an
almost perfect symmetry. The capacity of the brain cavity,
measured according to Flower's method, is 390 c.c.
“The masculine features of this skull, and particularly the
temporal ridges, are not quite as marked as those of another
skull of an adolescent male chimpanzee in the American Mu-
seum. The temporal ridges are slightly prominent, and in their
middle third, Over part of the frontal and the parietal bones,
not more pronounced than in some human crania. They are,
however, situated very high. Their upper lines or boundaries
touch each other over a part of the sagittal suture, a little
back of the bregma; while the lower lines approach to within
6 mm. of the Sagittal suture. The supraorbital ridges are
not very massive, although prominent to such a degree that,
when the skull rests on the occipital condyles and on the teeth,
the plane of the orbits is almost vertical. The sagittal crest is
insignificant; the occipital crest is high, but not very massive.
The zygomatic arches are less strong than they are in an
average white male; and the mastoids are small, even smaller
than in an average adult white female.
“The second dentition is incomplete; the third molars have
not reached the level of the opening of their sockets. The
condition of the sutures, so far as their patency is concerned,
does not bear the same relation to the stage of dentition as it
does in man: all the sutures of this skull are more or less
obliterated. There are no signs on any part of the skull that
point to the closure of any of the sutures as premature.
“The temporo-parietal sutures, with the exception of 8
mm. of the anterior end of the suture on the right side, are
both entirely closed and hardly traceable. The coronal suture
is partly open on the left, and wholly open on the right, up to
a point a little below the middle of the anterior border of the
parietal bone. At this point on each side, the lower portion
of the coronal suture appears as if it bent backward and con-
tinued as the anomalous suture; the upper portion of the
coronal, particularly on the right, is completely obliterated,
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 245
though still traceable. There are no signs left of the sagittal
and 1ambdoid sutures, and only the basal portions of the tem-
poro-Occipital articulation remain. The palatine sutures, also,
are entirely obliterated.
“The skull shows no important anomalies besides the divi-
Sion of the parietals.
“The divisions of the parietal bones begin on the left 32
mm., on the right 28 mm. (measured with a tape), above the
point of junction of the coronal and temporo-parietal sutures.
From the point where the anomalous sutures leave the coronal
Suture to the bregma the distance on the left is 44 mm., on
the right 42 mm.
“The excess of size of the left over the right parietal bone
along the coronal suture (6 mm.) compensates the greater
height of that portion of the right temporal squama which
articulates with the frontal bone. Measured across their
middle from the temporo-parietal suture, the two parietals
appear to be almost of equal size (left 82 mm., right 80 mm.).
In an antero-posterior direction, from the beginning of the
division to the middle of the parietal portion of the occipital
crest, both bones measure the same, namely, 75 mm.
“The division in the left parietal begins at a V-shaped cleft,
which is filled with a process of the frontal bone. There are
slightly distinct markings on the bone and a number of insular
Ossicles, which make it probable that the cleft had been origi-
nally much greater and was largely filled by a Wormian or,
rather, a fontanel bone, the lower border of which has subse-
quently united with the parieta1.
“For 30 mm. from its beginning the abnormal suture pro-
ceeds directly backward, and to this extent shows but little
obliteration. The original cleft has, it seems, extended up to
this point. From here the suture takes a slight bend upwards,
and proceeds almost directly upwards and backwards, be-
coming gradually obliterated, until it disappears at the tem-
poral ridge, 16 mm. from the median line. Originally the
suture must have terminated on the posterior border of the
parietal bone, not far from the lambda. The whole suture
shows fairly good serration. The coronal suture on this side,
as ºs.
**
tº
*…* -
•ºt. for ¥
Figs. 2, 3, 4. Skull of an adolescent male Chimpanzee, showing a bilateral
parietal division. *





246
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 247
*
below the division, shows serration about equal to that of the
abnormal suture; the obliterated portion above this was, so
far as can be seen, more simple.
“On the right side the division of the parietal may also
have begun with a cleft in the anterior border of the bone,
but, owing to the advanced state of obliteration of the upper
portion of the coronal suture on this side, the existence of the
cleft cannot be fully ascertained. Here also the abnormal
suture, at first wholly open, runs for the first 26 mm. directly
backwards; at this point the suture, still quite patent, takes
a turn somewhat sharper than that on the 1eft, and proceeds
for 16 mm. backwards and upwards; here it takes a second
turn, and proceeds almost directly upwards towards the Sagit-
tal suture. This last portion of the abnormal suture is con-
siderably obliterated, and on and beyond the temporal ridge
is scarcely traceable. The point at which the division has
reached the sagittal suture is situated a little behind the
middle of the latter. The abnormal as well as the open part
of the coronal suture on this side shows a simpler serration
than the corresponding sutures on the left side.
“In this specimen there is on neither side any encroach-
ment of the 1ower portion of the parietal bone upon the fron-
tal, such as Ranke lays stress on in the case of his orangs. A
second skull of an adolescent male chimpanzee, in the Museum
of Natural History, has a decided bend in the coronal suture,
not unlike that which Ranke describes, and which, as he
thinks, generally indicates an old parietal division; but in
this case the bend is situated between the inferior and superior
toundaries of the prominent temporal ridge, and apparently
owes its origin to the latter.”
The main interest in the case just described centers in the
so far unique (up to the publication of 37) location of the
abnormal sutures, and in the clearness with which the two
divisions appear as equivalent and of the same origin, although
one divides the parietal completely, while the other is restricted
to one of its angles.
In 1901 (73) there appeared in the Proceedings of the
©.
Fig. 5. Partial anterior parietal divisions in Apes.
(After Ranke.)


248
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 249
—ms
Anatomical Society of Great Britain and Ireland, with Some
notes on a demonstration before the Society by Dr. L. H.
Duckworth, a drawing of a “Chimpanzee Skull in Museum of
Copenhagen,” in which the left parietal shows a division much
like that on the same side in my case, but terminating more
anteriorly in the sagittal suture. No description whatever
accompanies this illustration.
CASEs OF INcom PLETE DIVISIONs of THE PARIETAL
BONES IN APES.
Orangs.-Among the 245 orang skulls examined by Ranke
(36, p. 314 et seq.), there were 13 with an incomplete parietal
division. This began invariably in the coronal border of the
parieta1, at the point where the coronal suture makes the bend
& ſº
. Fig. 6. The skull of a young Orang, showing a partial anterior parietal
division.
forward, and passed horizontally into the bone. All the 13
skulls with parietal divisions belonged to younger animals.
Gorillas. – Among 8 young gorilla skulls I showed a short
suture running backward from about the middle of the an-
terior border of the left parietal.
Chimpanzees. – Among II young Chimpanzee skulls there

250 Bulletin American Museum of Natural History. [Vol. XIX,
Was one with an incomplete suture in each parietal; the divi-
Sion proceeded from the middle of the coronal border to the
middle of each bone. sº
Gibbons. – Among 7o skulls of Hylobates concolor there is
no one with any parietal division.
The only other observer who reports incomplete parietal
sutures in apes is Frassetto (67). He saw a bilateral short
anterior division in three orangs, and in one of these there
was in addition on the left side a 6-mm.-long vertical fissure
in the posterior third of the superior border of the parietal.
MONEEYS : COMPLETE PARIETAL DIVISIONS.
Gruber's Case in a Monkey (15). — “Simia silenus” (appa-
rently adolescent, sex 2), presenting an oblique-vertical divi-
sion of the left parietal.
“The left parietal is divided, by an angular suture, com-
posed of a horizontal and a vertical branch, into two seg-
ments, one quadrangular, situated antero-superiorly, the other
triangular, situated postero-inferiorly.”
The horizontal branch of the anomalous suture, as seen on
the figure, begins a short distance above the squamo-coronal
point on the coronal border of the parietal, runs for a short
distance downward and backward, then makes an angular
turn and runs backward and somewhat upward, diverging
from the squamous suture to or slightly beyond the begin-
ning of the last fourth of the antero-posterior dimension of the
loone. At this point the “horizontal” branch meets the ver-
tical one, the two making a moderate obtuse angle open for-
ward and upward. The vertical branch is seen to run
upward and slightly backward, and end at or slightly before
the lambda. The anterior branch deserves more the term ob-
lique than horizontal.
The anomalous suture is moderately serrated and, with the
other cranial sutures, appears to be still open.
There is a large, rhomboidal Wormian bone in the lower
part of the coronal suture.
Welcker's Case (55). — The anterior-superior angle of the
right parietal of a Semnopithecus is separated by an anomalous
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 25 I
suture running in a curve (convex downward) from the middle
of the coronal to the middle of the Sagittal suture.
Coraini’s Case (a) (33). — A vertical division of the left pa-
rietal in an “Arctopithecus”; a partly obliterated oblique divi-
sion of the parietal bone
on the right side; and
a double division in the
1eft temporal squama.
Cranium regular; all °g.
normal sutures patent,
with the exception of
the anterior portion of
the right S Q u a mous
suture, which shows
some occlusion.
The 1eft parietal |bone Fig. 7. Gruber's case of a parietal division in a
is iºd. . . . º.º.º.º.
quadrate anterior and a :
narrow posterior trapezoidal portion.
On the right side an oblique, partially obliterated suture
runs from the Sagittal border of the parietal, from a point a
few mm. anterior to the superior termination of the suture on
the left side, to the sphenoidal angle.
The left temporal squama shows one partly oblique and
one vertical division (details given not sufficient to determine
exact location).
Coraini’s Case (b) (33). — A vertical division of the left
parietal bone in a Cercopithecus.
Cranium regular, all sutures patent, a persistence of metopic
suture. A bregmatic bone; Wormian bones about left pter-
ion; a separate bone in lambda. \,
The anomalous suture runs from the middle of the superior
to the inferior border of the parietal, diverging a little from
the lambdoid suture. º
Right parietal bone normal and of about the same size as
the left one.
Maggi’s Cases: Macacus cynomolgus (63). The right parie-
tal is divided into two by a vertical suture running from the
emº mº m 'mººn m sºme


252 Aulletin American Museum of AWatural History. [Vol. XIX,
Sagittal at the parietal foramen to the temporo-parietal suture.
Macacus cynomolgus (63). Frassetto mentions this case (70)
as one of a bilateral, complete, horizontal parietal division.
No description in 63. .
Cercopithecus (?) (63). An oblique, complete, unilateral
parietal division. The anomalous suture runs from the
superior part of the coronal to the inferior part of the lamb-
doid suture. No further particulars.
Cercopithecus patas (63). Mentioned in Frassetto as a case
of a complete vertical parietal division on the right side.
Frassetto's Cases: Cercopithecus (?) (68). A complete vertical
division of the left, incomplete, superior, similar and opposite
division of the right parietal.
Cercopithecus (67). A young animal. The left parietal is
divided by a complete vertical suture, and the posterior sep-
arate portion is subdivided into a superior and an inferior
segment by a horizontal suture (parietale tripartitum). On
the right parietal can be seen traces of a superior vertical
and a horizontal division.
MONIKEYS . IN COMPLETE PARIETAL DIVISIONS.
Maggi’s Cases: A Cercopithecus patas (63) shows a bilateral
incomplete vertical division starting on each side from the
Sagittal suture at the parietal foramen; also another superior,
vertical, incomplete division on the left side somewhat more
anteriorly. No one of these divisions is very long.
Cercopithecus campbelli (63). An incomplete division in the
superior border of the right parietal anterior to the parietal
foramen.
Ranke's Cases (36, p. 44). — A skull of Cynocephalus ursinus
shows an incomplete suture passing from the coronal border
into each parietal. e *
A.skull of Mycetes seniculus shows a 4-mm.-long suture,
passing from its anterior border into the right parietal.
Frassetto's Cases: Cercopithecus (?) (67, 7o). The superior
border of each parietal shows a short vertical division
(not opposite).
1903] Hrdlička, Parietal Bone in Man and Other Mammals. 253
Cebus fatuellus (67, 170). A horizontal fissure in the an-
terior border of each parietal somewhat below the middle
(right I.2, left o.5 cm.).
Cebus (67, 70). Traces of lower half of vertical suture in
the right parietal.
Résumé of Published Cases of Parietal Division in Apes and
Monkeys.
Apes. – I. A complete antero-posterior, nearly horizontal
division of the right parietal, with a remnant of a similar
division in the left parieta1, in an adolescent female orang
(Ranke).
2. A complete oblique division, upper part of lambdoid to
below middle of coronal suture, on the right side in an adol-
escent Orang (Frassetto).
3. A bilateral complete division, oblique (antero-superior)
On the left, vertical–horizontal (antero-superior) on the right
side, in a nearly adult male chimpanzee (Hrdlička).
4. A complete oblique antero-superior division in the left
parietal of a chimpanzee (Copenhagen Museum).
Incomplete horizontal divisions in the anterior portion of
the parietal observed by Ranke in 13 younger orangs, I gorilla,
and I chimpanzee, and by Frassetto in 3 orangs.
Monkeys. – I. A complete oblique (sphenoidal angle-
lambda) division in the left parietal of a “Simia silenus”
(Macacus silenus, or Semnopithecus silenus) (Gruber).
2. A complete vertical and a partly obliterated oblique
(sphenoidal angle-sagittal suture) division of respectively the
left and right parietal, in an “Arctopithecus '' (Coraini).
3–6. A complete vertical division in the left parietal bone
of an adolescent Cercopithecus (Coraini); in a Macacus cy-
nomolgus, right (Maggi); in a Cercopithecus patas, right
(Maggi); and in a Cercopithecus (?) on both sides, right in-
complete (Frassetto).
7. In one Cercopithecus (?) Frassetto found a complete ver-
tical and posterior horizontal suture on the left, and traces of
a vertical and a horizontal suture on the right.
254. Bulletin American Museum of Matural History. [Vol. XIX,
8. In one Cercopithecus (Maggi) a suture runs obliquely in
One of the parietals from the superior part of the coronal to
the inferior part of the lambdoid suture.
9. In a Macacus cynomolgus there is a bilateral antero-
posterior parietal division (Maggi).
Io. In a Semnopithecus an anomalous suture runs from the
middle of the coronal to the middle of the Sagittal suture
(Welcker).
Incomplete horizontal divisions in the anterior portion of
the parietal observed by Ranke in one Cynocephalus ursinus
and one Mycetes seniculus, and by Frassetto in a Cebus; in-
complete vertical divisions in the sagittal border of the
parietal are reported in two Cercopitheci by Maggi and in one
Cercopithecus by Frassetto, and vertical division in the in-
ferior portion of the parietal in one Cebus by Frassetto.
The more remarkable features of these records are the
occurrence of comparatively numerous vertical and some very
oblique, but only two (one case) of complete horizontal sutures
in the monkeys; the frequency of remnants of divisions and
their uniformly anterior location and horizontal direction in
the orangs; and the antero-superior divisions in the chim-
panzees. These conditions not only enlarge the field of pos-
'sibilities of parietal divisions, but they also directly urge a
thorough inquiry into the subject of development of the
parietal bones in various mammals.
IV. NEW MATERIAL.
To the preceding two categories of published cases I am
able to add some new observations of parietal divisions, par-
ticularly in monkeys. It was a parietal division in a monkey
skull that attracted my attention to the subject in 1897, and
since then I have been able to gather quite a number of other
cases of the anomaly in these animals.
My examinations have not been confined to monkeys, but
have extended, thanks to the courtesies of the various curators,
over a large series of human and various mammalian crania,
including the collections in the anthropological and zoölogical
departments of the American Museum of Natural History
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 255
and the anatomical collection in the Medical Department
(College of Physicians and Surgeons) of the Columbia Uni-
versity in New York, and parts of the anthropological collec-
tions in the Peabody Museum, Cambridge; the Museum of
Sciences and Art, Philadelphia; and the National Museum,
Washington. The material examined comprises nearly 3000
Indian and 4oo white and negro crania; a little over 4oo
skulls of apes and monkeys; and a little over 2000 skullS. of
other mammals. *
The most striking results of my search, so far as confined
to adolescent and adult crania, are the comparative frequency
of parietal divisions in monkeys, particularly in certain of
their species; the great scarcity of the anomaly in man; and
its complete, or almost complete, absence in other mammals.
Among I4 skulls of apes one specimen (chimpanzee) presented
a bilateral complete parietal suture; among 392 skulls of
monkeys of various kinds, there were 17 with complete and
35 with incomplete, single or multiple, parietal divisions. On
the other hand, among the 34oo human adolescent or adult
crania I saw but two with complete, none with large, and but
six with minor partial divisions in the parietal bone. The
two cases with complete sutures were those previously pub-
lished by Professor Putnam, in Prehistoric Indian Crania
from Tennessee. Among the skulls of various mammals
other than man, apes, and monkeys, there was but one with
a complete parietal suture, and even in this isolated case the
congenital character of the division is not as clear as would
be desirable. There were also found in these animal skulls
three cases with a separation of a portion of one of the angles
of the parietal; and there were many incomplete sutures in
the parietal bones; but these sutures are of a different origin
and meaning from the majority of those thus far considered,
and will, like the more or less normal parietal fissures in the
young, be dealt with in a special chapter.
GROUP I. CASES IN MAN.
Having received permission from Professor Putnam to
re-examine the two Tennessee Indian crania with parietal
256 Bulletin American Museum of Matural History. [Vol. XIX,
divisions, I am able to supplement the previously published
facts concerning the specimens by a few additional points of
interest and by illustrations of the divided parietals.
Putnam's 1st Case (26). Original Report. — A male adult
cranium, from a prehistoric stone grave in Tennessee, showing
an antero-posterior, almost horizontal, division of the left
parietal (spec. 27.205, Peabody Museum, Cambridge).
The skull is relatively broad and short, and shows a marked
occipital compression. “The left parieta1 is divided into two
quadrilateral pieces by a transverse serrated suture, crossing
the bone at one third its height above the squamous
suture. The transverse arc formed by the divided left par-
ietal exceeds that of the normal right parietal by One
fourth. The longitudinal arc of the left parietal is also
greater than that of the right parietal, and the left side of
the skull bulges upwards and outwards. The abnormal
suture encloses a pair of Wormian bones (size 3 of Broca's
scale).” “The coronal and sagittal sutures are simple and
all the sutures except the basilar are open.” The sutures of
the back of the skull are crowded with supernumerary bones
(over 20 in number).
Additional data and measurements. – The skull shows an
apparently congenital absence of both upper lateral incisors;
the other teeth are all present, well developed, and healthy.
The foramen magnum is very large (diam. antero-posterior
max., 3.7 cm.; diam. 1ateral max., 3.6 cm.), and of a somewhat
irregular hexagonal form; projecting into the foramen from
the middle of its anterior border is a o.4-cm.-high bony tubercle.
The skull is asymmetrical, which is partly due to the greater
height and bulging of the left parietal, and partly to the
Somewhat one-sided occipital compression. At least one, and
possibly two, of the separate bones in the lambdoid suture
must be considered as portions of the occipital squama.
Occlusion is manifested in the internasal, left masto-Occipital,
and about a few of the intercalated Ossicles in the lambdoid
suture. The skull as a whole is large and shows nothing
pathological. There is no division on the right side, but the
anterior border of the right parietal shows, in a position corre-
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 257
sponding to the point at which the anomalous suture begins on
the left, a marked indentation. e
Surface Measurements of the Two Parietal Bones.
Junction of the squamous and temporo-sphenoidal sutures
to the anterior termination of the anomalous division. . . . . . . left 4.6 cm. right —
Junction of the squamous and temporo-sphenoidal sutures,
to bregma. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . “ 13.4 “ “ 12.1 5 cm
Infero-superiorly at middle. . . . . . . . . . . . . . . . . . . . . . . . . . . . * * 14.5 “ ** I 2.2 “
(The posterior height cannot be measured accurately, the
1eft asterion being obliterated and the right affected by the
Wormian bones; but the height of the left parietal exceeds
also here quite considerably that of the right one. The
greatest height of the lower separate portion of the left parie-
tal is found about 2.0 cm. anteriorly to the lambdoid suture,
amounting to 5.5 cm. The Superior piece measures 6.9 cm.
along the lambdoid suture.)
Antero-posteriorly, from the middle of the coronal suture
to a point about midway between the asterion and lambda,
on the anterior boundary of the intercalated bones, the 1eft
parietal measures 12.6, the right 12.7 cm.; to the posterior
|boundary of the intercalated bones the left is 16.1, the right
I5. I Crm.
Putnam's 2d Case (26). Original Record. — A brachyce-
phalic, posteriorly somewhat compressed, adult male skull,
from a prehistoric stone grave in Tennessee, with an oblique
division of the left parietal and an angular separation of the
postero-inferior extremity of the right parietal (spec. 12797,
Peabody Museum).
“The extra suture (on left) springs from the left arm of the
1ambdoid suture at the junction of its middle and lower third,
and passes nearly horizontally half way across the parietal.
It is then deflected and runs towards the pterion. Posteri-
orly this suture is finely dentated, but anteriorly it becomes
simple and is so much obliterated that it is impossible to
trace its entire course. A large Wormian bone occurs in the
left arm of the lambdoid suture at and above the origin of this
anomalous suture.” -
[j'une, 1903.] 17
Fig. 8. Putnam's first case of parietal division. (Drawn from a
photograph.) -
Fig. 9. Putnam's first case of parietal division, posterior view. (Drawn
from a photograph.)


258
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 259
“The postero-inferior angle of the right parietal of this
skull is also developed from a separate center. It is united
with the main portion of the bone by a simple suture running
from the squamous suture almost horizontally till it ap-
proaches the lambdoid, when it turns downward and enters
this suture at a point opposite the middle of the squamous
loorder of the intercalated bone.”
“This skull has simple sutures which are open except near
the pterion” (coronal).
Additional Remarks. – The skull is very large, measuring
1825 c.c. in capacity. It shows but a little asymmetry, and
that mainly due to the artificial occipital compression. Noth-
ing pathological. A number of sutures show more or less
occlusion (partial synostosis in both malo-maxillary, left zygo-
matic, internasal, and all the intraorbital sutures; a com-
plete occlusion of the coronal suture on both sides below
the temporal ridge; traces of Occlusion about 1ambda and in
1eft lambdoid suture; and advanced occlusion in both sphe-
no-parietal and both temporo-Occipital articulations). The
lambdoid suture contains four smaller Wormian bones, one of
which is situated in a pronounced cleft from which begins the
left anomalous division.
The division on the left runs in an irregular way across the
whole length of the bone. The cleft from which it starts pos-
teriorly extends along the lambdoid suture from a point 2.o
cm. to one 5.5 cm. above asterion, and is nearly as deep as
high. The suture runs at first horizontally, then, somewhat
anterior to the middle of the parieta1, it bends downward, but
Soon bends again and proceeds forward, and finally forward
and upward, terminating at a point about 2.2 cm. above the
lower end of the coronal suture. The anterior portion of this
anomalous suture was squamous, the posterior Serrated. The
anterior fourth of the division is totally occluded and hardly
traceable; the occlusion diminishes backward, and the pos-
terior three fifths of the suture are largely patent.
The anomalous suture on the right side is open, and of a
moderately squamous character, the border of the lower over-
1apping somewhat that of the upper portion of the parietal.
2.
Fº
- *****.*
... • * *** ...,
*
ºt
*
*
rºx” ** ** º
.***
*** \ 4".
Jº * **
}~
CUT-C
Fig. Io. Putnam's second case of parietal division. (Drawn from a photograph.)
f*
Ji
C/ſº
<
Aſ
** .**
Fig. II. Putnam's second case of parietal division; the occipital borders of the parietals.



26O
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 26 I
The division begins posteriorly 2.3 cm. above the asterion and
passes at first upward, then forward and slightly downward
to the squamous suture. It separates a five-sided portion of
bone, which measures 5.5 cm. in its greatest length, and 4.o
cm. in its greatest height parallel to the lambdoid suture.
Near the middle of the lambdoid suture is a moderate-sized
intercalated bone (/), which may be of some importance;
the signification of this Ossicle will be referred to at the end
of this section.
Surface Measurements of the Two Parietals:
Temporo-sphenoidal point to anomalous suture. ...left, 2.2 cm. right —
& 8 & ſº { {
do. to bregma. . . . . . . . . . . . . I4.5 I 3. I CIT).
tº º to anomalous suture. . “ 3.o “ “
Infero-superior at middle } total. . . . . . . . . . . . . . . . “ 16.o “ “ 14.3 “
e to lower boundary of cleft “ 2.o “ “ to Suture 2.3 cm.
Asterion to lambda. . . to upper “ {{ { { “ 5.5 “ “
to lambda. . . . . . . . . . . . . . “ roo “ “ to lambda 1 1.5 “
Antero-posteriorly at middle. . . . . . . . . . . . . . . . . . . “ 14.2 “ about I4.o “
The chief of these additional facts is the possibility of trac-
ing the left division in the second case to, or at least very near
to, the coronal suture. The case is one of a complete antero-
posterior parietal division, and it would be erroneous to class
it, as Ranke has done, on the basis of the original data, among
the separations of the mastoid angle. The coexistence of an
infero-posterior suture on the right with the antero-posterior
one on the left side imparts to the case a considerable ad-
ditional interest.
The partial parietal divisions in man which I have found
comprise the following:
Case a. A calvarium of an adult male skull, No. 1 oo 3,
Medical Department, Columbia University, N. Y.
The calvarium comprises most of the frontal squama and
about the anterior # of each parietal. No abnormalities.
Advancing synostosis in both the Sagittal and coronal sutures.
The anterior portion of the right parietal shows an incom-
plete division. This begins at the Summit of a o.5 cm. deep
cleft in the anterior border of the bone, at the level of the
* Prof. Geo. S. Huntington’s Morphological Museum.
262 Bulletin American Museum of Watural History. [Vol. XIX,
Superior line of the temporal ridge, and runs for 1.7 cm. closely
to this line in a backward and upward direction. The division
was somewhat serrated; externally it shows an advanced,
internally a complete Occlusion. There are traces of a more
vertical suture that probably connected with the antero-
posterior one between the third and median fourth of the
latter, and bounded a large Wormian or fontanel bone situated
in the coronal suture. On the left side there is in the an-
terior border of the parietal a o.7 cm. deep cleft, located a
little above the temporal ridge, but no trace of any division.
Cases b, c, d. Skull of an adult white, sex uncertain;
No. 1 ooz, M. D., C. U., N. Y.
Calvarium somewhat asymmetrical; a broad, shallow de-
pression posteriorly to the coronal suture, and a somewhat
abnormal elevation of the Sagittal region at vertex. A large
epactal bone, with a moderate-sized separate bone above it in
1ambda. Synostosis of the Sagittal suture about obelion.
The left parietal bone shows in its anterior portion a o.6
cm. long, straight, slightly serrated incisure. The division
starts from the coronal suture between the two lines of the
temporal ridge, 6.7 cm. below the bregma, and is directed
lbackward and slightly upward. There is a trace of a simi-
lar incisure in the same location on the right parietal.
Two other calvaria showed similar short divisions situated
loetween (2), or a slight distance above (I) the temporal lines.
Case e. Skull of a female, Swiss, 65 years old; No. 613,
1899–1900, M. D., C. U., N. Y.
Present only parts of the temporal, Occipital, and right
parietal bones.
The postero-inferior portion of the parietal bone shows a
straight, slightly serrated, I.3 cm. long, ventrally occluded
division; the division begins in the posterior border of the
parietal, o.9 cm. above the asterion, and runs upward and
forward, in the direction of the parietal eminence.
There are remnants of the suturae mendosae and the squamo-
mastoid sutures.
Case f. Skull of a male white in advanced adult life
(about 55 y.), No. 1 oë7, M. D., C. U., N. Y.
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 263
-ms
The posterior portion of the left parietal bone shows rem-
nants of an oblique division. This begins o.7 above asterion
and runs upward and forward toward the parietal eminence.
The division can be plainly traced for 1.1 cm. externally, but
is completely occluded ventrally.
The skull shows nothing pathological and no further
anomalies. {
Among the total of six cases in this category there are four
with slight, more or less horizontal, anterior, and two with
moderate, oblique, postero-inferior divisions of the parietal,
all occurring in apparently normal adult skulls of whites.
New Instances of Anomalous Divisions of the Parietal
Bones in Monkeys.
The total number of apes, monkeys, and lemurs examined
by me for parietal divisions was 41 o, and of this there were:
| Chimpanzee. . . 2, divisions found in I
i Gorillae. . . . . . . . 7 & 4 ‘‘ ‘‘ o
Apes. . . . . . . . . . . . . . . . . . & Orangs. . . . . . . . . 3 { { ‘‘ ‘‘ o
| Gibbons........ 2 { { ‘‘ ‘‘ o
t I4. { { I
ſ Cynocephali.... 29 ( & & 2
i Cercopitheci. . . . 43 { { “ “ I
Chlororebi. . . . . . 3 ( { ‘‘ ‘‘ o
Old World Monkeys. . . . . . Cercocebi. . . . . . 7 ‘ ‘‘ o
Colobus. . . . . . . . I tº t ‘‘ ‘‘ o
Macaci . . . . . . . . I9'O * { “ “ 32
U 2 73 { { { { { { 35
ſCebi. . . . . . . . . . . 39 { { “ “ 9
Ateles. . . . . . . . . 4. I { { “ “ ,
Mycetes. . . . . . . . 2 { { ‘‘ ‘‘ o
American Monkeys.. . . . . ! Alouatas. . . . . . . 5 4 & “ “ o
Nyctipithecus.. I { { “ “ o
Hapale. . . . . . . . 3o * * ,
U II 8 i. “ “ 17
Lemurs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 & 4 “ “ o
T
O
t
3.
1.
.4
I
O
5
3
264 Bulletin American Museum of AWatural History. [Vol. XIX,
Of the 52 cases in monkeys there are 23 with but one com-
plete or incomplete division in one of the parietals, the other
bone showing no anomaly of this nature; in I instance there
is more than one division in one parietal bone and none in
the other; and in 28 cases there is one or more divisions in
each parietal. In 9 of the 52 skulls there are co-existing .
partial divisions on one (7) or both sides (2) in the temporal
squama, in line with, and looking like the extension of, the
parietal suture.
In order to facilitate their description the new cases can
be arranged, on the basis of the nature of the divisions, into
several groups. These are:
(1) Partial vertical (infero-superior) divisions;
(2) Complete “ { { & 4
(3) Partial and complete vertical-oblique (sagittal to mastoid border)
divisions;
(4) Partial and complete vertical sutures or fissures communicating
with a temporal division;
(5) Partial and complete more or less horizontal (antero-posterior)
divisions; and
(6) Compound cases. This last group includes some oblique divi-
S1OT1S.
The cases in detail are as follows:
GROUP 2. PARTIAL VERTICAL (INFERO-SUPERIOR) DIVISIONS
IN MONIKEYS.
Case I. Cynocephalus baboon, male, adolescent; No. 56,
M. D., C. U., N. Y.
There is a o.2 cm.-long vertical incisure in the sagittal por-
tion of the left parietal bone, near its middle. Besides this
the skull shows nothing special.
Case 2. Macacus rhesus, sex unknown, adolescent; No.
3775, A. M. N. H., N. Y.
There are plain traces of an occluded vertical division on
the sagittal portion of each parietal. The divisions begin
opposite each other, a little posterior to the anterior third of
the sagittal border of each bone (1.6 cm. from bregma, 3.o
* Zoëlogical Collection.
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 265
cm. from lambda), and both run straight downward, diverg-
ing slightly from the coronal suture. The left division can be
traced for 1.8 cm., the right one I.6 cm. -
The skull is symmetrical and without other exceptional
features. The parietal bones are almost equal in size.
Case 3. Macacus rhesus, male, adolescent; No. 3843, A. M.
N. H., N. Y.
The Sagittal portion of the right parietal bone is divided by
a vertical fissure. The division begins very near the middle
of the Sagittal border (2.05 cm. from bregma, 2.0 cm. from
lambda) and runs downward, parallel with the 1ambdoid
suture. It is patent for o.45 cm., but can be plainly traced
I.I cm. further.
The skull is symmetrical and without other abnormalities.
The right parietal is slightly lower over its anterior two
thirds, but throughout, except at the sagittal border, appre-
ciably longer, than the left.
Surface measurements of the two parietal bones:
Lower end of coronal suture to bregma. . . . . . . left 4.05, right 4.0 cm.
Infero-superiorly at middle. ..... . . . . . . . . . . . . “ 4.2 “ 4.o “
Asterion-lambda. . . . . . . . . . . . . . . . . . . . . . . . . . . “ 3.2 “ 3.2 “
Lower end of coronal suture to asterion. . . . . . . “ 4.6 “ 4.75 “
Antero-posteriorly at middle . . . . . . . . . . . . . . . “ 4.45 “ 4.65 “
Case 4. Macacus rhesus, male, adolescent; No. 3, M. D.,
C. U., N. Y.
There is a o.5 cm.-long straight incisure in the sagittal por-
tion of the left parietal bone. The division begins somewhat
anterior to the middle of the sagittal border (1.6-cm. from
lbregma, 2.2 cm. from lambda) and runs parallel to the coronal
Suture.
The skull is symmetrical, without any other remarkable
features. The two parietals are almost exactly alike in
1meaSurementS.
Case 5. Macacus rhesus, male, adolescent; No. 13, M. D.,
C. U., N. Y.
The Sagittal portion of the left parietal bone shows a o.95
cm. long, slightly serrated, straight division, running nearly
266 Bulletin American Museum of Natural History. [Vol. XIX,
*m--
parallel with the lambdoid suture. The division begins be-
tween the middle and fourth fifth of the sagittal border of
the bone (2.55 cm.
from bregma, I.7 cm.
from 1ambda).
There is no trace of
any division in the
right parietal. The
surf a c e measure-
ments of the two
lower show the right
parietal to be slightly
l longer, and in the
Fig. 12. Macacus rhesus (No. 3, Morphological Mu- sº -
seum. Columbia University) inéisure in the sagital anterior three fourths
border of the left parietal. -
also a pp reciably
§
**
higher than the left one.
The skull is fairly symmetrical. There is a small bregmatic
bone. No signs of any injury.
Surface measurements of the two parietals:
Point of junction of squamous and coronal
sutures to bregma. . . . . . . . . . . . . . . . . . . left 4. I5, right 4.2 cm.
Infero-superiorly at middle. . . . . . . . . . . . . . . . . “ 4.2 “ 4.45 “
Asterion to lambda ... . . . . . . . . . . . . . . . . . . . . . “ 3.2 “ 3.2 “
Squamo-coronal junction to asterion. . . . . . . . “ 4.7 “ 4.75 “
Antero-posteriorly at middle. . . . . . . . . . . . . . . . “ 4.95 “ 5.o “
Case 6. Macacus
rhesus, sex unknown,
adolescent; No. Ioé,
M. D., C. U., N. Y.
The left parietal
shows a 1.2 cm.-long
mark of a vertical
division, running from
the sagittal border,
parallel to the coronal
Suture. The division -
º - Fig. 13. Macacus rhesus (No. 13, Morphological Mu-
began slightly anter1- seum, Columbia University). Partial vertical division of
or to the middle of the left parietal.
the border (1.8 cm. from bregma, 2.1 cm from lambda).


1903.] Hrdlicka, Parietal Bone in Man and Other Mammals. 267
Skull symmetrical, no injuries or other anomalies. The
left parietal is slightly shorter inferiorly, but slightly longer
above the lowest third, than the right, the height of both
bones being very nearly equal.
Surface measurements of the two parietal bones:
Lower end of coronal suture to bregma... . . . .1eft 4.5, right 4.5 cm.
Infero-superiorly at middle . . . . . . . . . . . . . . . . . “ 4.3 “ 4.35 “
Asterion to lambda. . . . . . . . . . . . . . . . . . . . . . . . “ 3.2 “ 3.2 “
Lower end of coronal suture to asterion . . . . . . “ 4.6 “ 4.75 “
Antero-posteriorly at middle . . . . . . . . . . . . . . . “ 4.95 “ 4.8 “
Case 7. Macacus rhesus, female, young adolescent; No.
III, M. D., C. U., N. Y.
The parietal bones show each a vertical, straight, almost
entirely occluded division in their superior portion. The divi-
Sion on left begins in the Sagittal border of the parietal, 2.45
cm. from the bregma and 1.85 cm. from the lambda, that on
right 2.7 cm. from the bregma and 1.6 cm. from the lambda.
Both run almost parallel to the coronal suture. The division
in the left parietal can be plainly traced for 2.3 cm., that in
the right for 1.1 cm. g
The skull shows no injuries or other gross anomalies. The
two parietals are almost identical in measurements.
Case 8. Macacus rhesus, male, adolescent; No. 120, M. D.,
C. U., N. Y.
There is a partial vertical division in the sagittal portion of
the left parietal bone. The division begins slightly posterior
to the anterior third of the sagittal border (1.6 cm. from
bregma, 2.4 cm. from lambda). It is o.55 cm. long, but can
be traced, particularly by transmitted light, I.o cm. further;
it is straight, not serrated or squamous, and runs downward,
diverging slightly from the coronal suture.
There is no trace of any division on the right parietal. The
skull is symmetrical and without other gross anomalies. No
sign of any injury. The surface measurements of the two
parietals are very nearly equal.
Case 9. Macacus rhesus, sex unknown, young; No. 134,
M. D., C. U., N. Y.
The right parietal shows a plain trace of a vertical division,
268 Auletin American Museum of Natural History. [Vol. XIX,
running from the sagittal border of the bone to near the tem-
poral ridge. It begins 1.65 cm. posterior to the bregma and
2.65 cm. from the lambda, and runs nearly parallel with the
coronal suture. The skull is symmetrical, the parietals of very
nearly the same size. -
Case Io. Macacus rhesus, sex unknown, adolescent; No.
137, M. D., C. U., N. Y.
There are traces of a vertical division in the superior por-
tion of each parieta1. Both divisions begin posterior to the
middle of the Sagittal border, that on left 2.45 cm. from
bregma and I.65 cm. from 1ambda; that on right 2.95 cm.
from bregma and I. I 5 cm. from lambda. The Sagittal ex-
tremity of both is still open. The division on the left can be
traced for I.I cm., that on the right for 1.7 cm. Both are
straight and nearly parallel with the lambdoid suture.
The measurements show that the anterior two thirds of
the right parietal are slightly higher, while the length of the
two bones is very nearly the same.
The frontal bone shows on left, near the eminence, a 1.3
cm.-long, o.9 cm.-broad, and o.25 cm.-deep depression, and in
the floor of this are two small oval perforations. There are
no signs of fracture or inflammation, and the origin of the
depression is not clear. It stands in no perceivable connec-
tion with the parietal divisions.
Case II. Macacus rhesus, sex unknown, adolescent; No.
148, M. D., C. U., N. Y.
The right parietal shows a 2.4 cm.-long mark of a vertical
division, which begins in the middle of its sagittal border and
runs downward parallel with the coronal suture.
The skull is fairly symmetrical; there are no injuries or
Other anomalies. The skull being open the parietals cannot
loe properly measured.
Case I 2. Macacus cynomolgus, female, adolescent; No. 122,
M. D., C. U., N. Y. -
The left parietal bone shows near its middle traces of what
was probably originally a complete anomalous parietal divi-
Sion. The skull is symmetrical and without further anom-
alies.
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 269
Case 13. Macacus erythraeus, sex unknown, adolescent; No.
I613, A. M. N. H., N. Y.
The sagittal portion of each parietal bone shows a vertical
division.
The division on the left begins superiorly almost at the
middle of the sagittal border of the parieta1 (2.2 cm. from
bregma, 2.1 cm. from lambda), is o.4 cm. long, straight, and
paralle1 with the 1ambdoid suture. The division on the right
begins Sagittally near the posterior fourth of the border, passes
for o.45 cm. downward nearly parallel with the lambdoid
suture, then becomes considerably occluded, but can be fol-
lowed o.8 cm. further, running downward and somewhat for-
ward, in the direction of the parietal eminence.
The skull is symmetrical, the parietals nearly equal. No
injuries or other anomalies.
Case I4. Macacus erythraeus, sex unknown, adolescent; No.
4347, A. M. N. H., N. Y.
The right parietal bone shows a short vertical incisure
between the middle and posterior thirds of its sagittal border.
From this incisure a plain mark of an occluded division runs
downward, parallel with the lambdoid suture, to the tem-
poral ridge (3.2 cm. from the Sagittal, I.o cm. from the squam-
ous suture).
The skull is symmetrical and free from signs of injuries
and other anomalies. The right parietal bone is somewhat
higher, but at middle a little shorter than the left one.
Surface measurements of the two parietals:
Squamo-coronal junction to bregma. . . . . . . . . left 4. I, right 4.3 cm.
Infero-superiorly at middle... . . . . . . . . . . . . . . “ 4.o.5 “ 4.2 “
Asterion to lambda . . . . . . . . . . . . . . . . . . . . . . . “ 2.85 “ 2.95 “
Squamo-coronal junction to asterion......... “ 4.7 “ 4.7 “
Antero-posteriorly at middle. . . . . . . . . . . . . . . “ 4.7 “ 4.6 “
Case I 5. Cebus, sex unknown, young; No. 86, M. D.,
C. U., N. Y. -
The superior part of the anterior portion of the left parietal
bone shows one, and the sagittal portions of both the left and
right parietal each two marked clefts.
The anterior division on left is o.4 cm. long and directed
27O Bulletin American Museum of Matural History. [Vol. XIX,
downward and backward. The more anterior of the left
Sagittal clefts begins superiorly nearly at the middle of the
border, is 1.1 cm. long, and runs downward and slightly
forward. The second left Sagittal cleft begins between the
third and last fourths of the border, is o.35 cm. long and is
also directed downward and slightly forward.
On the right side, the more anterior of the two clefts begins
o.3 cm. posteriorly to the bregma, is o.4 cm. long, and runs
nearly parallel with the coronal suture, showing a slight ten-
dency to turn backward. The more posterior cleft on this
side begins superiorly between the middle and 1ast thirds of
the Sagittal border, is o.6 cm. long, and passes downward with
a tendency to curve backward. (P1. IX.) &
The skull is fairly symmetrical and free from other anom-
alies.
Case 16. A teles ater, young, sex unknown; No. 187, M. D.,
C. U., N. Y.
The sagittal portion of the left parietal shows a partly
occluded I.o cm.-long division, running parallel with the
1ambdoid suture. .
The skull is symmetrical; the right parietal bone is both
slightly longer and broader than the left one.
Case 17. Hapale, sex unknown, young; No. 58a, M. D.,
C. U., N. Y.
The right parietal bone shows a remnant of, in all prob-
ability, a formerly complete
vertical–horizontal suture.
The remaining part of the
division begins distally in
the sagittal border of the
parietal, o.3 cm. anteriorly
to the lambda. It runs
with several bends and
curves downward and
..;&#áš:;";"; forward over the eminence
parietal. and to near the temporal
ridge, where it becomes totally occluded.
The skull shows no other special features. The right parie-

1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 27 I
tal bone is very slightly longer, and a little lower than the
left one. º
GROUP 3. compleTE VERTICAL PARIETAL DIVISIONS IN
MONIKEYS.
Case 18. Macacus rhesus, male, advanced adolescent; No.
Io, M. D., C. U., N. Y. ity
The parietal bones show each a vertical division.
The division in the left parietal begins slightly anterior to
the point between the most anterior and middle thirds of the
Sagittal border of the bone (1.6 cm. posterior to the bregma,
3.6 cm. anterior to the lambda). It runs in a slightly wavy
course downward and a little backward to the upper boun-
dary of the temporal ridge, beyond which no marks of any
further division are visible. Below its superior two fifths the
division shows advancing occlusion.
The right parietal bone shows a superior and an inferior
fissure, but these two are joined by a plainly traceable line of
Occlusion; it is evident that originally the bone was separated
into two by a complete vertical suture. The division began
Superiorly between the middle and posterior third of the sagit-
tal border (3.2 cm. from bregma, 2.0 cm. from lambda) and
ran parallel with the lambdoid suture. The inferior open seg-
ment reaches the lower boundary of the temporal ridge.
The normal sutures are still all patent. The anomalous
Sutures were, so far as can be seen in their remnants, of a
very slightly squamous nature, the border of the anterior
Overlapping those of the posterior portions.
The skull is symmetrical and the two parietals differ but
insignificantly in size, as can be seen from the following sur-
face measurements:
dº
Junction of squamous and coronal sutures to
bregma. . . . . . . . . . . . . . . . . . . . . . . . . left 4.4, right 4.45 cm.
Junction of squamous and coronal sutures to
asterion . . . . . . . . . . . . . . . . . . . . . . . . “ 4.8 “ 4.85 “
Asterion to lambda. . . . . . . . . . . . . . . . . . . . . . . . “ 3.35 “ 3.3 “
AnterO-posteriorly at middle. . . . . . . . . . . . . . . . “ 5.4 “ 5.3 & &
{ { { % { {
Infero-Superiorly “ “ . . . . . . . . . . . . . . . . 4.65 4.6
272 Au/Zetin American Museum of AWatura/ Aistory. [Vol. XIX,
*=–
—s
The same skull shows, without any sign of an injury in any
part, a separation of a portion of the lower border of the
nasal bones, and
two Supranasal os-
sicles. (Fig. I5 and
P1. VII.)
Case I 9. Ma-
cacus cynomolgus,
Sex P, nearly adult;
No. 38, M. D., C.
U., N. Y.
The cr a nium
presents well-
marked traces of a
complete vertical
division of the
right parietal.
The anomalous
suture consists of
Fig. 15. Macacus rhesus (No. 10, Morphological Museum, a Superior, Open,
Columbia University). Showing a separation of the lower
portion of the nasal bones, and two independent supranasal 7 mm.-long eXtrem-
ossicles. ity, which begins
slightly posteriorly to the middle of the sagittal border of
the right parietal, and runs almost parallel with the vertical
axis of the bone; and of an obliterated, but traceable part,
which proceeds from the open extremity downward, in the
same direction, to the temporal border of the parietal.
Eleven mm. from the sagittal border a small open slit is seen
in the course of the division.
Measurements of the two parietal bones:
Length in middle. . . . . . . . . . . . . . . . . . . . . . . . . . . left 5.05, right 5.4 cm.
“ squamo-coronal point to asterion..... “ 4.45 “ 4.5 “
Hight, § { { { “ “ bregma. . . . . . “ 4. I “ 4.25 “
“ in middle. . . . . . . . . . . . . . . . . . . . . . . . . . “ 4. I5 “ 4. I5 “
“ asterion to lambda. . . . . . . . . . . . . . . . . “ 3.o “ 3.o “
The right bone is throughout larger antero-posteriorly, and
is also slightly higher in front than the left.
The skull as a whole is not perceptibly asymmetrical, shows

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PARTLY OBLITERATED, PARIETAL DIVISIONS.
VERTICAL
MACACUS RHESUs, MALE (No
UNIVERSITY).


























1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 273
no signs of injuries and no further anomalies. All the nor-
mal sutures are open and there are no Wormians.
Case 2.0. Macacus rhesus, young adolescent, sex unknown.
No. IoI, M. D., C. U., N. Y.
The right parietal shows two extremities of a vertical suture,
connected by traces of the same.
The Superior end of the division begins 2.4 cm. posterior to
bregma, 2.1 cm. anterior
to lambda, is straight,
and o.4 cm. long. The
1ower end, nicely ser-
rated, is o.7 cm. in
length. The interven-
ing traces of the com-
plete suture show that
this was of a nearly
Straight course and ran
parallel to the lamb-
doid suture, crossing the
parietal eminence. The Fig. 16. Macacus ºesus (No. 101, Morphological
eminence is somewhat ºw). Wºº, ºnly
rough and irregular.
Surface measurements of the two parietals show that the
divided bone is slightly longer than the one on the opposite
side:
Bregma to lambda . . . . . . . . . . . . . . . . . . . . . . . . left 4.3, right 4.5 cm.
Temporo-sphenoidal junction to bregma. . . . . . “ 4.4 “ 4.5 “
* ( & & 4 “ to asterion . . . . . . “ 4.2 “ 4.2 “
Asterion to lambda..... . . . . . . . . . . . . . . . . . . . . “ 3.4 “ 3.5 “
Antero-posteriorly at middle. . . . . . . . . . . . . . . “ 4.55 “ 4.8 “
Infero-superiorly “ “ . . . . . . . . . . . . . . . . " 4.4 “ 4.35 “
The skull is fairly symmetrical and without further anom-
alies.
GROUP 4. VERTICAL-OBLIQUE PARIETAL DIVISIONS IN
MONEEYS.
Case 21. Macacus rhesus, female, adolescent; No. 37, M.
D., C. U., N. Y.
[?'une, 1905.] 18

274 Bulletin American Museum of Matural History. [Vol. XIX,
Both parietals show remnants of a vertical-oblique division,
which began superiorly in the sagittal border of each bone,
2.0 cm. from bregma and 2.4 cm. from 1ambda, and ended on
each side in or near the mastoid angle. The division on the
left is partly, that on the right entirely, occluded. Both divi-
sions ran nearly parallel with the coronal suture up to the
parietal eminence, but began to curve backward between this
and the temporal ridges. The deflection is most marked in
the neighborhood of the ridges. The unoccluded portion of
the left division shows it to have been of a slightly squamous
nature, the border of the anterior portion of the parietal over-
lapping that of the posterior. (P1. VIII.)
The skull is fairly symmetrical, without other anomalies and
without any signs of injury. The right parietal bone exceeds
the left slightly in all the measurements.
Surface measurements of the parietals:
Lower end of the coronal suture to bregma. . .1eft 4.0, right 4.1 cm.
Infero-superiorly at middle. . . . . . . . . . . . . . . . . “ 4. I5 “ 4.3 “
Asterion to lambda. . . . . . . . . . . . . . . . . . . . . . . . “ 3.2 “ 3.3 “
Lower end of the coronal suture to asterion... “ 4.1 5 “ 4.35 “
Antero-posteriorly at middle. . . . . . . . . . . . . . . . “ 4.8 “ 5.1 “
Case 22. Macacus rhesus, young, sex unknown; No. 47,
M. D., C. U., N. Y.
The specimen presents a division of the right parietal bone
by a complete vertical-oblique suture, and traces of a similar
division on the left parietal.
The right anomalous division begins superiorly on the
sagittal border of the parietal, I.7 cm. posterior to the bregma
and 2.5 cm. anterior to the lambda. It runs in a slightly
wavy course for 1.8 cm. parallel to the vertical axis of the
bone, then bends in a broad curve backward, and proceeding
backward and downward terminates, after making a small
loop, at the beginning of the parieto-mastoid border. The
whole suture is patent, and of the squamous character, the
anterior division of the bone overlapping the posterior. In
the terminal 5 mm. of the suture the border of the overlapping
anterior portion shows a well-marked serration.
On the Sagittal border of the left parietal, o.85 cm. pos-
BULLETIN A. M. N. H. Vol. XIX, PL. VIII.
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BULLETIN A. M. N. H. Vol. XIX, Pl. IX.
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FIG. I.-CEBUS, YOUNG (No. 86, MoRPHOLOGICAL MUSEUM, CoLUMBIA
UNIVERSITY). PARIETAL INCISURES.
FIG. 2.-MACACUS RHESUS (No. 47, MORPHOLOGICAL MUSEUM, CoLUM-
BIA UNIVERSITY). SHOWING PARIETAL DIVISIONs.



















































1903.] Hrdližka, Parietal Bone in Man and Other Mammals. 275
teriorly to the bregma, we find a trace of obliterated division
which may be followed, with some difficulty, downward and
backward, to near the beginning of the parieto-mastoid bor-
der. The border of the anterior portion of the bone along
the upper part of this scar-like mark is elevated into a dis-
tinct ridge. (P1. IX.)
The skull shows no signs of injuries and no anomalies be-
sides the parietal divisions. All the ordinary cranial sutures
are patent. There are no Wormian bones. The border of
the Occipital squama projects, on an average, about I mm.
above the plane of the parietals (a condition quite common
in macaques).
The two parietals show the following proportion (surface
measurements):
Length along Sagittal suture. . . . . . . . . . . . . . . . .1eft 4.2, right 4.2 cm.
Squamo-sphenoidal point to asterion. . . . . . . . . “ 4.25 “ 4.25 “
{ { { { “ “bregma. . . . . . . . . . “ 3.9 “ 4.o.S. “
Hight in middle. . . . . . . . . . . . . . . . . . . . . . . . . . . “ 4.3 “ 4.o “
Asterion to lambda. . . . . . . . . . . . . . . . . . . . . . . . “ 2.95 “ 3. I “
The length of the two bones is about the same. In hight
the right parietal predominates anteriorly and posteriorly, the
left parietal in the middle.
Case 23. Macacus rhesus, male, young adolescent; No.
I 18, M. D., C. U., N. Y.
The skull presents a considerably occluded, vertical-oblique
division of the right parietal bone, and a trace of a similar divi-
sion on the left parietal.
The right anomalous division begins superiorly almost ex-
actly in the middle of the Sagittal border of the parietal. It
proceeds for 3.2 cm. in a straight course and parallel to the
1ambdoid suture, to the temporal lines, then curves and runs
backward and downward across the lines, and in an irregular
course to the mastoid angle. The suture is distinct, but
entirely occluded, with the exception of two small segments
just above and below the temporal ridge. On the ventral
surface of the bone the whole division is represented by a dis-
tinct, though shallow and narrow groove.
The external surface of the left parietal bone shows traces
:
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276 Bulletin American Museum of Natural History. [Vol. XIX,
of an occluded division, which began directly opposite the
division on the right, ran vertically for nearly 2 cm., then
curved backward and ran backward and downward. It can
|be traced to within I cm. of the asterion. This division is
much less distinct than that on the right, and is not marked
internally. Along the vertical part of the same, the border
of the anterior portion of the parietal is elevated above that
of the posterior.
Measurements of the two parietals:
Length along Sagittal border. ... . . . . . . . . . . . . . left 4.7, right 4.7 cm.
“ squamo-coronal to squamo-lambdoid
{ { & 4 { {
* * is ſº tº e º ºs e tº e s e e s is e s º is a e g º is a sº e º & 5. O 5 5. I5
gº tº e º (º “ 4.7 “ 4.5 “
e s e e º s is e e s is a e < * “ 4.6 “ 4.6 “
squamo-lambdoid point to lambda.... “ 2.85 “ 2.8 “
The two bones dif-
fer slightly in indi-
vidual measurements,
|but their area, which
may be represented
by an average of all
the measurements
taken on each bone,
is almost equal. The
inequalities do not af-
fect the symmetry of
the skull, which shows
no further anomalies,
save a small Wormian
loone in bregma, and
no signs of injuries. All the normal cranial sutures are open.
Fig. 17. Macacus rhesus (No. 118, Morphological
Museum, Columbia University). Vertical-oblique
parietal division.
GROUP 5. VERTICAL PARIETAL DIVISIONs witH EXTENSION
INTO THE TEMPORAL SQUAMA, IN MONKEYS.
Case 24. Macacus rhesus, female, adolescent; No. 157 II,
A. M. N. H., N. Y.
The right parietal bone shows a partial vertical division
affecting its inferior portion, and this division connects ex-

1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 277
ternally with an incisure in the temporal Squama, running
in the same direction.
The parietal division can be traced but o.35 cm. above the
squamous suture, which it meets at a point very near the
middle between the squamo-lambdoid and squamo-coronal
junctions.
The temporal fissure runs from a point very slightly an-
terior to that at which the parietal division reaches the Squa-
mous suture for o.35 cm. Straight downward, then makes two
little loops backward, and ends in the upper portion of the
depression above the base of the zygoma.
The skull is fairly symmetrical and shows no signs of any
injury or any other anomalies. The right parietal bone is al-
Fig. 18. Macacus rhesus (No. 15711, A. M. N. H.). Partial temporo-parietal division.
most throughout its whole extent longer and anteriorly quite
considerably higher, but posteriorly lower, than the left One.
Surface measurements of the two parietals:
Hight, squamo-coronal junction to bregma. . .1eft 3.95, right 4.5 cm.
“ infero-superiorly at middle. . . . . . . . . . . “ 4.2 “ 4.2
“ asterion to lambda. . . . . . . . . . . . . . . . . . “ 3.5 “ 3.2 “
Length, squamo-coronal junction to asterion. . “ 5. “ 5.o “
“ o.5 cm. above squamo-coronal junc-
tion and asterion. ... . . . . . . . . . . . “ 5.o “ 5.1 “
“ in middle. . . . . . . . . . . . . . . . . . . . . . . . . “ 4.35 “ 4.5 “
{{ { 6 &
{ { along Sagittal suture. ... . . . . . . . . . . . . 3.45 3.65

278 Bulletin American Museum of Matural History. [Vol. XIX,
Case 25. Macaciis rhesus, female, adolescent; No. 14, M.
D., C. U., N.Y.
The left parietal bone shows a complete, the right a partly
obliterated, vertical parietal division, and both these divisions
are externally slightly prolonged downward by a fissure in
each temporal Squama.
The division in the left parietal begins superiorly in the
Sagittal border of the bone, I.7 cm. from bregma and 2.1 cm.
from lambda, and runs in a nearly straight course, converging
slightly from above downward with the lambdoid suture, to
a point on the squamous suture distant 3.0 cm. from the
squamo-coronal junction and 1.8 cm. from the asterion. At
this point the division is met by the o.35 cm.-long temporal
incisure, which runs downward in the same direction with
the parietal suture. The anomalous division is slightly squa-
nous in character, the border of the anterior overlapping that
of the posterior portion of the bone.
The division in the right parietal begins inferiorly directly
above a o.2 cm.-long vertical fissure in the temporal squama,
at a point distant 3.0 cm. from the Squamo-coronal junction
and 1.8 cm. from asterion. The parietal division soon be-
comes occluded, but can be easily followed upward, as a
quite broad mark, to the sagittal fourth of the bone, where it
curves forward and becomes indistinct. One centimeter
above the squamous suture there is in the just-mentioned
mark a second, short, patent segment of the division; while
2.1 cm. above the squamous suture there diverge from the
mark two moderate elevations. The anterior of these eleva-
tions runs in a slightly wavy course to within a short distance
from the superior fourth of the coronal; the posterior, in a
similar course, to within a short distance from the posterior
fourth of the sagittal suture. The part of the parietal bone
immediately above these elevations is slightly depressed. It
appears as if the elevations and the depression above them
represented the borders of inferior and superior portions of
the parietal bone, separated formerly by now occluded divi-
sions. (P1. X.) -
Neither the right parietal bone nor any other part of the
BULLETIN A. M. N. H. Vol. XIX, PL. X.
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MACACUS RHESUS, FEMALE (No. 14, MORPHOLOGICAL MUSEUM, CoLUM-
BIA UNIVERSITY). BILATERAL VERTICAL PARIETAL DIVISION, EXTENDING
ON EACH SIDE SLIGHTLY INTO THE TEMPORAL SQUAMA. THE SUTURE IN
THE RIGHT PARIETAL Is NEARLY OBLITERATED.











































































































































1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 2 79
skull shows any signs of violence or any pathological condi-
tion. Judging from this fact and the symmetry of the in-
ferior part of the division on the right to that on the left side,
it is probable that the marks on the right parietal are rem-
nants of anomalous divisions of the bone. The divisions Su-
perior to the parietal eminence must have become occluded
very early, and the direction of the marks may have been
modified somewhat by an unequal growth of the various por-
tions of the bone.
The parietal region of the skull is slightly asymmetrica1.
The right parietal bone is throughout somewhat higher and
at middle also slightly longer than the left one.
Surface measurements of the two parietals:
Squamo-coronal junction to bregma. . . . . . . . . .1eft 4.2, right 4.5 cm.
Infero-superiorly at middle. . . . . . . . . . . . . . . . . “ 4.o “ 4.15 “
Asterion to lambda. . . . . . . . . . . . . . . . . . . . . . . . “ 2.7 “ 2.9 “
Squamo-coronal junction to asterion. . . . . . . . . “ 4.8 “ 4.8 “
Antero-posteriorly at middle. . . . . . . . . . . . . . . . “ 4.8 “ 4.95 “
Case 26. Macacus rhesus, sex unknown, adolescent; No.
Io?, M. D., C. U., N. Y.
Fig. 19. Macacus rhesus (No. 107, Morphological Museum, Columbia University).
Temporo-parietal division.
The inferior portion of the right parietal bone is separated
by a vertical division, and this is met at the squamous suture

280 Bulletin American Museum of Watural History. [Vol. XIX,
by a division in the temporal bone, running in the same
direction. -
The parietal division is patent from the inferior border of the
bone to 1.4 cm. above the squamous suture, which it meets
nearly at the middle point between asterion and the squamo-
coronal junction. The course is upward and slightly forward;
it reaches the lower boundary of the temporal ridge, beyond
which it is not traceable. The superior o.4 cm. of the divi-
sion shows several points of Occlusion.
The temporal division begins slightly posterior to the point
at which that of the parietal meets the squamous Suture and
runs downward to above the base of the zygoma, where ex-
ternally it becomes obliterated. Slightly below and anter-
iorly to the end of the superior division another fissure begins
and runs for about o.6 cm. through the zygomatic fossa and
along the middle of the base of the zygoma. Upon examin-
ing the right glenoid fossa, we find that anterior to the Glas-
serian fissure the fossa is traversed by still another slightly
wavy, I.o.5 cm. long division, which begins on the basal
surface of the zygoma and ends before reaching the median
loorder of the temporal bone. The superior and this basal
temporal division run in nearly the same line.
The very unusual condition just described is explained
when we remove the parietal bones and examine the skull
ventrally. It is then seen that the superior divisions, as well
as that in the glenoid fossa, penetrate the bone and form on
the inside of the skull parts of a slightly serrated suture,
which runs from the Superior border of the squama downward
and inward to and over the border of the basilar portion of
the temporal bone anterior to the Glasserian fissure, and con-
nects with the basilar extremity of the temporo-sphenoidal
suture. There are a few small points of obliteration in the
lyasal end of this anomalous division.
The skull shows absolutely no sign of any injury, or any
sign of restitution (porosity or new bone formation) along the
temporal or parietal divisions. The skull is symmetrical and
free from other anomalies. The right parietal bone is longer
and slightly higher, and the right temporal squama is equally
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 281
slightly longer and higher than the same parts on the left side.
Surface measurements of the two parietals:
Squamo-coronal junction to bregma. ... . . . . . . left 4.3, right 4.5 cm.
Infero-superiorly at middle. . . . . . . . . . . . . . . . . “ 4.75 “ 4.8 “
Asterion to lambda . . . . . . . . . . . . . . . . . . . . . . . . “ 3.2 “ 3.2 “
Squamo-coronal junction to asterion. . . . . . . . . “ 4.9 “ 5.1 “
Antero-posteriorly at middle. . . . . . . . . . . . . . . . “ 4.15 “ 4.3 “
The exact nature of the parieto-temporal division in this
case must remain somewhat uncertain until 1arge numbers
of other specimens have been reported upon. There are fac-
tors, such as the absence of injury and signs of restitutive
processes; the involvement of the whole temporal bone ven-
trally, while there are interruptions externally; the signs of
Occlusion at the extremities of the division; the beginning of
the temporal division at a little distance from the point at
which the parietal division reaches the temporal squama and
in a notch, which was observed in all other cases of parieto-
temporal division; and the similarity of location of the di-
visions with that in cases where there is no doubt as to the
anomalous nature of the divisions; all of which favor more or
less the assumption that in this case, also, we have examples of
anomalies. What creates doubt as to this conclusion are the
unusual location of the temporal division and another fact,
not yet mentioned: when we separate the edges of the divided
bones, we see that in parts of both the parietal and temporal
bones the borders do not show articular surfaces, but an open
cellular structure.
Case 27. Macacus, species and sex unknown, adolescent;
No. 1 Ioz 2, A. M. N. H., N. Y. ſº
The specimen presents on each side an anterior episcºua-
mous bone, which, as comparison with other macaque skulls
shows, is either formed at the expense of, or, (more probably)
is a separation, of the extremity of the sphenoidal angle of each
parietal; and there are two incisures, one on each side, in
the superior portion of the temporal squama, one connecting
with, and the other in the neighborhood of, the suture that
bounds superiorly the separate ossicles.
The separate bones are triangular in shape. The one on
282 Bulletin American Museum of Watural History. [Vol. XIX,
the left measures o.3 cm. along the coronal and o.5 cm. along
the squamous suture; that on the right is slightly larger.
The temporal incisure on the left is o.7 cm., that on the
right o.4 cm. long. The left incisure runs parallel with the
temporo-sphenoidal suture; that on the right side passes ver-
tically downward, but at its end makes a slight curve for-
ward and would end, if prolonged, in the upper portion of
the sphenoidal portion of the temporal.
Posterior to the beginning of the left temporal incisure the
Squamous suture turns downward and runs to the extremity
of the division, thus forming a deep notch, and leaving un-
covered a narrow strip of the subsquamous portion of the
parietal bone. This condition shows that the incisure is not
recent. (P1. XI.)
Ventrally, the conditions are almost the same as externally;
the separate bones have all the appearance of being portions
of the parietal bone.
The skull shows no signs of any injury or any pathological
condition. It is symmetrica1, and, with the exception of an
oblong Ossicle between the left nasal bone and superior max-
illa, is free from further anomalies. -
Surface measurements of the two parietals show the left
loones to be inferiorly slightly longer, while superiorly the
condition is reversed, the right bone being very slightly the
1Onger.
Hight, lower end of the coronal-suture to
bregma. . . . . . . . . . . . . . . . . . . . . . . . left 4.3, right 4.3 cm.
“ infero-superiorly at middle. . . . . . . . . . . “ 3.8 “ 3.8 “
“ asterion to lambda. ... . . . . . . . . . . . . . . “ 2.2 “ 2.1 5 “
Length, lower end of coronal suture to asterion “ 4.45 “ 4.25 “
“ antero-posteriorly at middle. . . . . . . . . “ 4.7 “ 4.7 “
“ bregma to lambda . . . . . . . . . . . . . . . . . “ 3.45 “ , 3.55 “
Case 28. Cebus albifrons, male, nearly adult; No. 8309,
A. M. N. H., N. Y.
The inferior portion of the right parietal bone shows, near
its middle, a vertical division, and this is met externally by
a partial division in the temporal squama running in the
same direction.
BULLETIN A. M. N. H.
Vol. XIX, Pi. XI.
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OF THE SPHENOIDAL PROCESS OF THE PARIETAL
INTO THE TEMPORAL
FIG. 2.-CEBUS ALBIFRONS (No
FIG. I.-MACACUS (No







































































1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 283
The parietal division begins inferiorly in the border of the
bone and runs upward, with a few serrations, parallel with
the coronal suture. It is patent from the border of the
parietal to o.6 cm. above the external line of the squamous
suture, but can be traced o.8 cm. further upward.
The temporal fissure begins superiorly in a notch in the
border of the squamous portion, situated slightly anterior
to the point at which the parietal division meets the squa-
mous suture. It is o.5 cm. long, but probably a part of its in-
ferior extremity is obliterated. The division is nearly straight
and ends in the upper part of the fossa above the base of the
zygoma. (P1. XI.) *
The skull shows no signs of any injury or other anomalies,
and is symmetrical. The right parietal bone is longer and at
middle higher, but posteriorly slightly lower than the left one.
Surface measurements of the two parietals:
Junction of coronal and fronto-malar sutures to
bregma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . left 5.o, right 5.0 cm.
Infero-superiorly at middle . . . . . . . . . . . . . . . . . “ 5. I 5 º' 5.4 “
Asterion to lambda . . . . . . . . . . . . . . . . . . . . . . . . “ 3.45 “ 3.3 “
Junction of coronal and fronto-malar sutures
to asterion. . . . . . . . . . . . . . . . . . . . . . . . . . . . ‘‘ 4.6 “ 4.75 “
Antero-posteriorly at middle . . . . . . . . . . . . . . . . “ 5.5 “ 5.7 “
Case 29. Cebus hypoleucus, sex unknown, adolescent; No.
Io'720, A. M. N. H., N. Y.
There is a vertical division in the left parietal, extending
from the inferior border of the bone to the temporal ridge;
and a temporal division, following directly in the course of
the parietal one and ending in the fossa above the base of the
Zygoma.
Externally both divisions begin at the squamous suture, at
a point slightly anterior to the middle between the lower end
of the coronal suture and the asterion. Their course is almost
parallel with that of the coronal suture. The total external
length of the parietal division is 1.9 cm., that of the temporal
o.6 cm. The parietal division shows considerable occlusion
advancing from above; the inferior extremity of the ten-
poral fissure shows also some occlusion. (P1. XII.)
284 Bulletin American Museum of Natural History. [Vol. XIX,
The skull is symmetrical. There are no signs of any in-
jury or other anomalies. The left parietal bone is inferiorly
very slightly longer, at middle very slightly shorter, and at
middle and posteriorly slightly lower than the right One.
Surface measurements of the two parietals:
Junction of squamous and malo-frontal sutures, left 4.75, right 4.75 C.
Infero-superiorly at middle . . . . . . . . . . . . . . . . . “ 4.8 “ 5.o “
Asterion to 1ambda . . . . . . . . . . . . . . . . . . . . . . . . “ 2.9 “ 3.o “
Junction of squamous and malo-frontal sutures, “ 4.65 “ 4.6 “
Antero-posteriorly at middle. . . . . . . . . . . . . . . . “ 5.05 “ 5.0 “
GROUP 6. ANTERO-POSTERIOR PARIETAL DIVISIONS IN
M ONE EYS. -
Case 30. Cynocephalus mormon, male, adolescent; No.
I 21,. M. D., C. U., N. Y.
The left parietal bone is partly divided by a suture, which
begins distally in a notch in the sagittal border of the bone,
2.5 cm. from the bregma and o.6 cm. from the lambda. The
division is 2.5 cm. long, quite straight, slightly serrated, and
runs in a downward and slightly forward direction to the
parietal eminence. The median fourth of the division shows
some occlusion. The parietal eminence on this side is repre-
sented by a circular, rather broad but low bulging, with a
moderate central depression. A shallow groove runs from
this depression forward toward the coronal suture, represent-
ing the anterior part of a complete antero-superior division.
There is no trace of any inflammatory action, and the in-
dications are against the depression being due to an injury.
(Pl. XII.)
The sagittal third of the divided parietal is somewhat more
bulging than the same region on the right, and the whole left
parietal bone is slightly higher, but shorter, than the right
O1162.
Case 31. Macacus rhesus, male, adolescent; No. 145, M. D.,
C. U., N. Y.
This specimen presents a beautiful division of each parietal
by a curved antero-posterior suture.
The suture begins on the frontal border of the parietal
BULLETIN A. M. N. H. Vol. XIX, PL. XII.
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FIG. I.- CEBUS HYPOLEUCUs (No. 10,720, A. M. N. H.). PARIETO-
TEMPORAL DIVISION ON THE LEFT SIDE.
FIG. 2.-CYNOCEPHALUs MoRMON (No. 121, MORPHOLOGICAL MUSEUM,
CoLUMBIA UNIVERSITY). INCOMPLETE VERTICAL DIVISION IN THE LEFT
PARIETAL.


























1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 285
loones, the left 2.25 cm., the right 1.7 cm. from bregma. They
both proceed in a gentle, symmetrical curve backward, to end
each on the occipital border of the parietal bones, I cm. from
lambda. Both sutures are open and of a squamous charac-
ter, the border of the inferior position of each bone overlap-
ping that of the superior One.
Eleven mm. below the termination of the right anomalous
suture, the occipital border of the parietal is divided by a 1.5
cm.-long, open fissure, which runs parallel with the suture.
(P1. XIII.) -
Measurements of the two parietals:
Length, along Sagittal border. . . . . . . . . . . . . . . left 3.5, right 3.5 cm.
“ squamo-coronal point to asterion..... “ 4.45 “ 4.5 “
Hight, & 4 ( * * “ “ bregma. . . . . “ 4.5 “ 4.2 “
“ at middle. ... . . . . . . . . . . . . . . . . . . . . . . “ 4.8 “ 4.7 “
“ asterion to lambda. ... . . . . . . . . . . . . . . “ 4. I “ 4.o “
The left parietal is higher than the right, especially anter-
iorly; this, however, does not affect appreciably the sym-
metry of the whole cranium.
The skull shows no further anomalies and no signs of any
injury. The normal sutures are all pervious. There are no
Wormians. -
Case 32. Macacus rhesus, Sex unknown, adolescent; No.
195, M. D., C. U., N. Y.
The left p a riet a 1
bone shows a 3-milli-
meters - long, slightly
oblique incisure in its
posterior b or der, a
short distance above
the asterion. No other
anomalies.
Case 33. Macacus
erythraeus, sex u n -
known, adolescent ;
fe
".
7,
%
No. 16I 6, A. M. N. H. Fig. 20. Macacus erythraeus (No. 1616, A. M. N. H.).
N. Y. Division in the left parietal.
3.
|
The left parietal bone shows a 1.35-cm.-long, antero-pos-

286 Bulletin American Museum of Natural History. [Vol. XIX,
terior division in the middle of its posterior, and a o.3 cm.-
deep, V-shaped notch, situated immediately above the tem-
poral ridge, in its anterior portion.
The posterior division runs in a slightly wavy course for-
ward and a little downward; its anterior half is occluded.
The notch in the anterior portion of the bone is filled with an
Ossicle.
The skull is asymmetrical in the parietal region; the left
parietal bone is slightly smaller and less bulging than the
right one. 4.
Surface measurements of the two parietals:
Squamo-coronal junction to bregma. ... . . . . . . left 4.0, right 4. I cm.
Infero-superiorly at middle. . . . . . . . . . . . . . . . . “ 4.3 “ 4.35 “
Asterion to lambda. ..... . . . . . . . . . . . . . . . “ 3. I “ 3.2 “
Squamo-coronal junction to asterion. . . . . . . . . “ 4.35 “ 4.35 “
Antero-posteriorly at middle. . . . . . . . . . . . . . . . “ 4.85 “ 5.1 “
There are no signs of any injury or further anomalies.
Case 34. Cebus capucinus, male, young; No. 164, M. D.,
C. U., N. Y.
There is a horizontal incisure o.9 cm. long in the anterior
portion of the right and a similar incisure o.6 cm. long in the
anterior portion of the 1eft parietal bone, both situated a
short distance above the sphenoid angle.
Skull symmetrical, parietals nearly equal. No injuries or
further anomalies. (Compare Cebi 5050, IIo37, 63.23.)
Case 35. Ateles belzebub, sex unknown, adolescent; No.
I 19, M. D., C. U., N. Y.
There is a horizontal fissure o.3 cm. long in the anterior
portion of the left parietal, slightly below its middle. The
temporal ridge passes beneath the fissure.
The skull shows no other exceptional features.
Case 36. Ateles wellerosus, male, nearly adult; No. 14484,
A. M. N. H., N. Y.
The left parietal bone shows an oblique antero-posterior,
well serrated, but for the most part obliterated anomalous
division.
The still visible part of the suture begins distally on the
occipital border of the parietal, 5 mm. above the asterion.


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1903 || Hrdlička, Parietal Bone in Man and Other Mammals. 29 I
On the right side the vertical division, an o.8-cm-long,
narrow cleft, begins superiorly in the sagittal border of the
parietal, o.7 cm. anterior to the lambda, and runs slightly
divergent with the lambdoid suture. In addition the bone
shows, on its anterior third and somewhat below the tem-
poral ridge, a o.9-cm.-long, patent segment of an antero-pos-
terior division. A slight
notch in the anterior
lborder of the bone at
about the same hight
marks probably the
original anterior ter-
mination of this divi-
Sion.
The skull is sym-
metrical; the parietals
show but insignificant
differences in dimen-
sions. No signs of
injury and no further
anomalies.
The case is allied to
those of Cebi 5050 and
IIo37, A. M. N. H.
(q.v.).
Case 4I. Cebus, ad-
olescent, species and
sex not determined;
No. 143, M. D., C. U. R
The skull shows two ºf: Gººs " " " "):
parietal divisions, one
oblique and one horizontal, in the right, and a partial oblique
division in the left parietal.
The oblique divisions begin on each side by a cleft in the
postero-superior angle of the parieta1, and run, as narrow
clefts, downward and somewhat forward. The left division
is 6.5 millimeters long. That on the right is in two seg-
ments, being interrupted by a narrow band of Ossification; it
&

292 Bulletin American Museum of Matural History. [Vol. XIX,
measures in toto 3.1 cm.; its inferior extremity is lost, just
above the temporal ridge. #3
The horizontal division on the right begins in the posterior
border of the parietal, o.9 cm. below the lambda and 1.6 cm.
above the asterion;
it is straight, o.5 cm.
long and Serrated.
(Pl. XV.)
The skull is sym-
metrical and with-
out further anom-
alies; the parietals
are nearly equal.
Case 42. Ateles
ater, sex unknown,
adolescent; No. 1628,
A. M. N. H., N. Y.
There are two pro-
nounced incisures in
the left, and one in
the right parietal
lbone.
Of the incisures on
the left, one is situ-
ated in the anterior,
and the other in the
superior portion of
the bone. The an-
terior division be-
gins distally I.6 cm.
Fig. 24. A teles ater (No. 1628, A. M. N. H.). Parietal te
tº Ateles ater (No. 1628, *** ** above the point of
R.
- junction of the coro-
nal and malo-frontal sutures, 3.5 cm. below the bregma,
and o.8 cm. below the temporal ridge. The incisure is
o.8 cm. long, slightly wavy, and directed backward and very
slightly downward. The second division on the left side be-
gins superiorly between the third and last fourths of the sagit-
tal border of the parietal (2.4 cm. from bregma, o.8 cm. from

BULLETIN A. M. N. H.
Vol. XIX, PL. XV.
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FIG. 2.
N. H.). PARTLY OBLITERATED DI-
LES (NO. I4,484, A. M.
E.
VISION OF THE LEFT PARIETAL,
I.— AT
FIG.
, COLUMBIA UNIVERSITY).
MORPHOLOGICAL MUSEUM
• I43,
NO
FIG. 2.-CEBUS (
PARIETAL DIVISIONS.







































































































1903.] Hrdlička, Parietal Aone in Man and Other Mammals. 293
1ambda), is 1.4 cm. long, and runs obliquely downward and
somewhat forward.
The incisure in the right corresponds to the anterior divi-
sion in the left parietal. It begins distally I.6 cm. above the
point of junction of the coronal and malo-frontal sutures, 3.6
cm. below the bregma and o.8 cm. below the temporal ridge.
It is o.9 cm. long and
runs in a nearly straight
course backward and
somewhat downward.
. The skull is quite sym-
metrical. No signs of
injuries or further anom-
alies. The right parietal
is higher in its middle
three fifths than the left
one (infero-superiorly at
middle, right 4.5 cm.,
1eft 4.2 cm.), but other
measures of the bones
are equal. There are
traces of occlusion in the
lower fourths of the coro-
na1 sutures.
Case 43. A teles, male,
young; No. 6313, A. M.
N. H., N. Y.
The skull shows five
marked incisures in the
right, and two in the left R.
parietal lbone. Of those #. A teles (No. 6313, A. M. N. H.). Parietal
on the right, two are in
the anterior, two in the posterior, and one in the Superior
portion; of those on the left, one is in the anterior and one in
the posterior portion of the bone.
The lower of the two anterior divisions on the right begins
distally I.I cm., the higher one 2.0 cm. above the junction of
the coronal and malo-frontal sutures, or, respectively 3.1 cm.

294 Bulletin American Museum of Matural History. [Vol. XIX,
and 2.2 cm. from the bregma. The inferior division is situated
a short distance above the temporal ridge, is o.45 cm. long,
straight, and directed backward and slightly downward. It
runs up to the temporal ridge. The superior incisure is also
o.45 cm. long and straight, and runs parallel with the lower
division.
Of the two posterior incisures on the right, the lower begins
distally o.9 cm. above the asterion, or 1.8 cm. from the lambda,
while the higher one begins distally at the lambda itself. Both
the incisures are straight, and run forward and slightly down-
ward; the lower one is I.o cm., the upper one o.7 cm. long.
The sagittal division begins superiorly o.7 cm. from the
1ambda, is o.7 cm. long, and runs in a downward and forward
direction.
The anterior division on the 1eft begins distally o.9 cm.
above the point of junction of the coronal and malo-frontal
sutures, and slightly above the temporal ridge; it is o.35
cm. long, straight, and runs backward and slightly downward
to the ridge.
The posterior left division begins distally o.9 cm. above the
asterion, or 1.85 cm. from the lambda, is I.o cm. long, straight,
and directed forward and slightly downward.
The skull is quite symmetrical, the parietals nearly equal.
There are no signs of injuries, or other anomalies.
Case 44. Ateles, species not determined (probably A. vel-
lerosus), male, adolescent; No. 13690, A. M. N. H., N. Y.
The right parietal bone shows two partial divisions, one in
its Sagitta1, the other in its posterior border.
The vertical incisure begins superiorly at very near the
middle of the Sagittal border, is I.35 cm. long, nearly straight,
and runs downward and somewhat backward. The lower
fifth of the division shows advanced occlusion.
The posterior incisure is o.5 cm. long, and straight; it
begins distally in the middle of the Occipital border of the
parietal, and runs forward parallel with the horizontal axis of
the bone.
The skull shows several other peculiarities. The fontanel
at bregma is filled with a quite large, somewhat diamond-
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 295
shaped separate bone; and there is on each side in the lower
part of the coronal suture a number of moderate-sized to Com-
paratively large Wormians. On the left, one of these Wor-
mian bones enters o.85 cm. deep into the anterior portion of
the parietal bone, just below the temporal ridge. (Pl. XVII,
Fig. I.)
The two parietals are equal in height, but the right bone is
1onger than the left one.
Surface measurements of the two parietal bones:
Point of junction of the squamous and tem-
poro-sphenoidal sutures to bregma. . . . . . .1eft 6.2, right 6.2 cm.
Infero-superiorly at middle. . . . . . . . . . . . . . . . . ‘‘ 6. I ‘‘ 6. I “
Asterion to 1ambda. ... . . . . . . . . . . . . . . . . . . . . “ 3.9 “ 3.9 “
Point of junction of the squamous and tem-
poro-sphenoidal sutures to asterion . . . . . . “ 4.05 “ 4.25 “
Antero-posteriorly at middle. ... . . . . . . . . . . . . ‘‘ 6. I ‘‘ 6.2 “
GROUP 7b. INSTANCES OF COMPOUND COMPLETE PARIETAL
DIVISIONS IN MONE EYS.
Case 45. Cercopithecus callitrichus, female, adult; No.
I3923, A. M. N. H., N. Y.
The left parietal bone shows a complete vertical division,
and this is met at the squamous suture by an incisure in the
temporal squama running in the same direction. On the
right side there is a complete separation by an oblique suture
of the postero-inferior portion of the parietal, and in addition
traces of a vertical division.
The anomalous division in the 1eft parietal bone begins
Superiorly at a point distant o.85 cm. from the 1ambda and
2.25 cm. from the bregma. It passes downward and slightly
forward to the temporal ridge, where it makes a bend, and
after that descends more directly downward, running nearly
parallel with the coronal suture. With the exception of a
few points of occlusion the division is patent, and it shows a
noderate serration.
The temporal fissure begins superiorly at a point slightly
anterior to that at which the parietal meets the squamous
suture, is o.65 cm. long, though traceable a little further
296 Bulletin American Museum of Natural History. [Vol. XIX,
downward, and runs with a slightly wavy course to the upper
portion of the supra-zygomatic fossa.
On the right side both the vertical and the oblique divisions
begin inferiorly at the same point, which is distant I.4 cm.
from the asterion and 2.6 cm. from the point of junction of
the temporo-parietal and temporo-sphenoidal sutures. The
vertical division is almost entirely occluded, but can be traced
for 2.2 cm. above the Squamous suture, running upward and
slightly backward. Six millimeters above the border of the
temporal bone we find in the course of the vertical division a
moderate-sized oblong foramen, and there is a similar opening
at exactly the same hight in the left parietal suture.
The oblique division on the right passes backward and up-
ward, terminating o.8 cm. above the asterion. The piece of
bone it separates is of a triangular shape and measures o.8
x 1.4 x 1.65 cm. An oblong opening, slightly larger than that
in the right vertical, is found also in the anterior portion of the
oblique division. On the left side there is no oblique or an-
tero-posterior division discernible, but I. 1 cm. vertically
above the squamous and o.3 cm. from the lambdoid suture
is a quite large, ventrally occluded foramen, which possibly is
a remnant of such a separation. The portion of the left
parietal below the slightly oblique line which passes from the
foramen in the vertical, through the more posterior isolated
foramen, to the lambdoid suture, is somewhat flattened.
The skull is symmetrical, and there is no trace of any injury.
The left malar bone is divided by a serrated, horizontal, still
patent suture. (Pl. XVI.)
Of the two parietals the left one is a little higher anteriorly
and posteriorly, but slightly lower at middle, and shorter both
inferiorly and at middle, than the right one. The surface
measurements are as follows:
Junction of squamous and temporo-sphenoidal
sutures to bregma. . . . . . . . . . . . . . . . . . . . . 1eft 4.3, right 4.1 cm.
Infero-superiorly at middle. . . . . . . . . . . . . . . . . “ 3.7 “ 3.9 “
Asterion to lambda . . . . . . . . . . . . . . . . . . . . . . . . “ 3.2 “ 3.0 “
Junction of squamous and temporo-sphenoidal
sutures to asterion. ... . . . . . . . . . . . . . . . . . “ 3.7 “ 4.o “
Antero-posteriorly at middle. ... . . . . . . . . . . . . “ 4.3 “ 4.4 “
BULLETIN A. M. N. H.
Vol. XIX, PL. XVI.
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CERCOPITHECUS CALLITRICHUS (No. 13,923, A. M. N. H.).
PARIETAL
DIVISIONS. MALAR DIVISION.






















































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VoI. XIX, PL. XVI 1.
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H.).
FIG. I.--ATELES (No. 13,690, A. M. N.
RIGHT PARIETAL.
COLUMBIA
46, MORPHOLOGICAL MUSEUM
VERTICAL PARIETAL DIVISION.
FIG. 2. — MACACUS RHESUS (NO.
UNIVERSITY).



























1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 297
Case 46. Macacus rhesus, sex unknown, adolescent; No.
46, M. D., C. U., N. Y.
The specimen shows a complete vertical, and traces of a
partial horizontal division of the right, and remnants of two
divisions, one vertical and one oblique, on the left parietal
bone.
The vertical suture on the right begins superiorly a little
posterior to the middle of the sagittal border of the bone (2.6
cm. from the bregma, I.85 cm. from the lambda). It runs
very nearly parallel with the lambdoid suture up to the tem-
poral ridge, at which it curves slightly backward. It ter-
1minates 3.1 cm. posterior to the squamo-coronal junction and
1.8 cm. anterior to the asterion. -
The suture is throughout patent. It is throughout mod-
erately squamous in character, the border of the anterior
overlapping that of the posterior portion of the parietal; at
the same time the suture shows externally a fair serration.
The horizontal division can be traced as a slight, straight
elevation, running from the middle of the posterior border of
the parietal I.2 cm. forward, parallel with the sagittal suture.
The vertical division on the left parietal bone began sagi-
tally exactly opposite the similar division on the right side.
It is completely Occluded, but can be plainly traced for 1.3 cm.,
running straight downward parallel to the lambdoid suture.
The oblique division on the left, probably the counterpart
of the horizontal One on the right, begins as an open fissure 3
millimeters below the 1ambda. The fissure becomes soon
occluded, but can be traced, running in a straight line in the
direction of the parietal eminence, for I.o cm. (P1. XVII,
Fig. 2.)
The skull is fairly symmetrical and shows no further anom-
alies. The right parietal is slightly longer at middle, but
slightly lower, especially at middle, than the left one.
Surface measurements of the two parietal bones:
Squamo-coronal junction to bregma. ... . . . . ... left 4.3, right 4.2 cm.
Infero-superiorly at middle. . . . . . . . . . . . . . . . . “ 4.2 “ 3.9 “
Asterion to lambda . . . . . . . . . . . . . . . . . . . . . . . . “ 3.2 “ 3.2 “
Squamo-coronal junction to asterion. . . . . . . . . “ 4.9 “ 4.9 “
{ { & 4 & 4
Antero-posteriorly at middle. . . . . . . . . . . . . . . . 5.o 5. I
298 Bulletin American Museum of Natural History. [Vol. XIX,
Case 47. Macacus rhesus, sex unknown, adolescent; No.
5o, M. D., C. U., N. Y.
The skull presents a complete, partly occluded vertical
division of the right, and a fully patent vertical–horizontal
division of the 1eft parietal bone.
The division on the right side begins superiorly somewhat
posterior to the middle of the sagittal border of the parietal
(about 2.6 cm. from bregma, I.8 cm. from lambda) and, a
portion of the Sagittal suture immediately in front being
obliterated, it appears like a prolongation of the posterior,
patent segment of the suture. Four and a half millimeters
from the line of the sagittal suture the division becomes totally
Occluded, but, if the skull is inclined in a certain way to the
light, the line of the division can be quite plainly traced. This
Imark runs almost straight downward, parallel with the lamb-
doid suture, and in the lower third of the parietal joins the
inferior open portion of the division. This latter portion,
which shows the character of a squamous suture, with the
border of the posterior piece overlapping that of the anterior
One, makes a moderate knee-like deflection forward and down-
ward, and after a course of 1.5 cm. reaches the temporo-
parietal suture, slightly anterior to the middle point between
the squamo-coronal junction and asterion. But the division
does not end here. Externally, following directly in its
course, but soon bending forward, is a squamous suture, which
runs to the temporo-sphenoidal suture and apparently has
separated a portion of the temporal squama 2.1 cm. long by
o.55 cm. in its greatest hight. Ventrally, the right parietal
loone is seen to reach throughout its anterior two thirds un-
usually low, much more so than the left one; the overlapping
of the inferior portion by the temporal squama is very con-
siderable, averaging nearly o.5 cm. in hight. The parietal
division proceeds in the same direction in which it reached
the squamous suture to the border of the bone. The portion
of the parietal anterior to the division reaches the wing of the
sphenoid. The squamous suture, which appears externally
like the continuation of the parietal division, is seen running
immediately below the anterior half of the lower border of
BULLETIN A. M. N. H. Vol. XIX, Pl. XVIII.
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MACACUS RHESUS (No. 50, MORPHOLOGICAL MUSEUM, CoLUMBIA UNIVERSITY).
PARIETAL DIVISIONS.











































































































1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 299
this portion. The hight of the temporal squama from the
external border of the glenoid fossa to the beginning of the
fronto-parietal suture is 1.7 cm. on the left, I.95 cm. on
the right (including the o.55 cm. high separate portion).
The left parietal shows what is probably the lower portion
of a formerly complete vertical division, and a horizontal
suture passing from this to the posterior border of the bone.
The vertical division begins inferiorly at a point distant 1.8
cm. from the squamo-coronal junction and 3.o from the aste-
rion. It is of a squamous character, the border of the pos-
terior separate portion overlapping that of the anterior one.
It runs in a nearly straight course for 1.7 cm. upward, parallel
with the coronal suture. At this point it ends and is joined
at nearly a right angle by the antero-posterior suture. The
Separated piece of the parietal being removed, a small oblique
incisure is seen in the angle between the two divisions, and
above this incisure the surface of the bone bears slight traces
of an extension of the vertical suture.
The antero-posterior division is also nearly straight and of
a squamous character, the border of the lower overlapping the
anterior half of the border of the upper separate part. It runs
parallel to the sagittal, but converges somewhat from before
backward with the squamous suture. It terminates in the
posterior border of the parietal, o.5 cm. above the asterion.
(P1. XVIII.)
The skull is quite symmetrical. It is larger than the aver-
age macaque skull at a similar period of life, and shows ven-
trally marked impressions of cerebral convolutions. The
right parietal bone exceeds the left one in its antero-posterior
dimensions, while the hight, except along the coronal suture,
shows externally no difference. Ventrally the right parietal
is also higher.
Surface measurements of the two parietal bones:
Squamo-coronal junction to bregma. . . . . . . . . left 5.o, right 4.75 cm.
Infero-superiorly at middle. . . . . . . . . . . . . . . . . “ 4.7 “ 4.7 “
Asterion to lambda. . . . . . . . . . . . . . . . . . . . . . . . . “ 3.o “ 3.o “
Squamo-coronal junction to asterion. . . . . . . . . “ 4.8 “ 5.1 “
{ { § {
4.95 5.25
& ©
Antero-posteriorly at middle . . . . . . . . . . . . . tº
3OO Bulletin American Museum of AWatural History. [Vol. XIX,
The middle third of the sagittal suture is obliterated; other
normal sutures are patent. There is a moderately large, ir-
regularly quadrilateral bregmatic bone.
Case 48. Macacus rhesus, sex P, adolescent, No. Io2, M.
D., C. U., N. Y.
This skull presents a number of puzzling features. The
parietal bones show several divisions, and two of these appear
to be prolonged into the adjoining parts of the frontal and
temporal squamae. The majority of the divisions have the
appearance of, and in all probability are, genuine anomalous
parietal sutures, but two of the smaller divisions on the right
side suggest by their location and character more a possible
injury, of which, however, there are no distinct signs present.
After many repeated and careful examinations, it seems equally
improbable that all the divisions are natural anomalies, or
that they are all due to some injury. The most probable fact
is that we have here a combination of highly interesting
anomalous divisions with some secondary effects of violence,
— a violence, perhaps, of some peculiar nature.
The left parietal bone is divided into three large, more or
less quadrilateral segments, two anterior and one posterior, by
two true anomalous sutures, one vertical and one horizontal.
The vertical suture begins sagitally 2.2 cm. posterior to bregma
and 2.1 cm. anterior to lambda, proceeds almost parallel to the
coronal suture, reaches the squamous suture I.5 cm. posterior
to the junction of this with the coronal, bends and runs o.85
cm. forward and downward into a notch in the border of the
temporal Squama, then bends again and passes for a little
over two millimeters directly downward into the squama it-
self. Ventrally the division continues from this point directly
forward as the spheno-parietal suture, bounding a long, nar-
row, Subsquamous sphenoidal process of the parietal bone.
A similar, though shorter sphenoidal process exists on the oppo-
site side.". The course of this vertical suture in the left parie-
tal is almost straight, with the exception of a moderate double
curve above the temporal ridge. The suture is of a squamous
* Similar processes exist in other macaques, with the result that while externally
there is a fronto-temporal, we have internally a parieto-sphenoidal articulation; and
this condition is not restricted to these monkeys.
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 3Ol
nature, particularly inferiorly. Superiorly the posterior seg-
ment of the parietal overlaps slightly the superior anterior
one, while inferiorly the conditions are reversed, the inferior
anterior portion overlapping to a marked degree the posterior
Oſle.
The horizontal or antero-posterior division on the left be-
gins in the anterior border of the parietal 2.5 cm. above the
Squamo-coronal junction, or 1.9 cm. inferiorly to the bregma,
and proceeds with a moderate curve backward and slightly
downward to a little below the middle of the vertical suture.
The suture is partly squamous, the superior overlapping
somewhat the inferior portion of the parietal. From the an-
terior extremity of this suture a partial division passes into
the frontal squama. This division is obliterated, but can be
plainly traced; it is straight, 1.2 cm. long, and directed
toward the frontal eminence.
There is not the slightest trace of any injury on the left side
of the skull, and the character of the divisions is such that
they cannot be regarded as anything else than anomalous
sutures. The coexistence of the incisure in the temporal
Squama can, I think, be attributed to a mechanical inter-
ference in the growth of that part of the squama caused by a
Somewhat uneven growth (the anterior part is even now
higher) of the underlying portions of the two segments of the
parietal. The frontal division is more difficult to be accounted
for, nevertheless a method suggests itself by which it may
have been produced by the influence of the horizontal pari-
etal division. This point will be dealt with at the end of this
paper.
The right parietal bone of the skull under consideration pre-
sents a partial vertical and a partial horizontal suture, which
separate a quadrilateral piece of the antero-superior portion
of the bone. The piece is much like the antero-superior
segment of the left parietal, and is very probably of a similar
origin, the sutures separating it being true anomalous divi-
sions. The vertical suture begins on the sagittal border of the
parietal two millimeters anterior to that on the left, namely,
2.25 cm. from the bregma and 2.1 5 cm. from the lambda. It
3O2 Bulletin American Museum of Natural History. [Vol. XIX,
is nearly straight, parallel to the coronal suture, and inferiorly
slightly squamous, the adjoining part of the parietal over-
lapping here the separated segment. Eighteen millimeters
below the sagittal suture the vertical meets an antero-pos-
terior division. This latter begins 2.1 cm. below the bregma,
hence two millimeters lower than the antero-posterior di-
vision on the left. It runs I.4 cm. backward and slightly
upward, then makes a sharp, irregular bend and runs 3 mm.
upward, after which it bends again and runs 7 mm. back-
ward, parallel with the Sagittal suture, and meets the verti-
cal division. From the bend and from the angle between
the horizontal and vertical sutures, two incisures, nearly
straight, and for the most part obliterated, the inferior I.I
cm., the Superior o.9 cm., run backward and downward into
the parietal. Ventrally it is seen that these two divisions
have joined, separating a piece of bone 2.3 cm. long by o.7
cm. in maximum hight. This piece is subdivided by a
vertical slit, which is directly continuous with the vertical
division, but is obliterated dorsally, into two smaller por-
tions.
On the same parietal (right) we find still another division.
It is an incomplete antero-posterior suture of squamous na-
ture, beginning 3.15 cm. below the bregma, 1.55 cm. above
the squamo-coronal junction, and ending within 7 millimeters
from the lambdoid suture. The course of this division for
the anterior three fourths of its extent is parallel to the squa-
mous suture, but then it makes a moderate curve upward. The
border of the lower portion of the parietal along this division
is higher than the upper portion and overlaps the same. The
more superior partial antero-posterior division is but slightly
squamous, but there also the border of the inferior tends to
overlap that of the Superior portion; but in the two shorter
divisions which begin from this superior horizontal suture, the
conditions are reversed, the superior borders distinctly over-
lapping the inferior. On the left, as remarked before, the
border of the superior overlaps that of the inferior portion.
The inferior horizontal division is mostly closed, only 1.2
cm. of its anterior end remaining patent. It opens by a
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 3O3
slight cleft into a wide, 2.5 millimeters deep, V-shaped in-
dentation in the anterior border of the parietal. A similar
indentation is found on the left side in the same location.
Five millimeters below the just-described inferior horizontal
division on the right parietal, just where the temporal ridge
crosses, there is in the border of the frontal bone (seen with
the parietal removed) a V-shaped cleft, from which leads for-
ward and downward a peculiar suture which completely
Separates a portion of the frontal squama. Externally this
suture is somewhat obliterated, but can be traced forward,
running below the temporal ridge, on to the malar process of
the frontal bone, and from here in nice serrations to a foramen
situated a little more than one millimeter below the malo-
frontal suture. It reappears again in the orbit running in a
curve above and to the wing of the sphenoid. Ventrally the
whole course of the suture can be followed without any diffi-
culty, though in places there are signs of obliteration. The
division passes downward and forward to the angle between
the squama and orbital portion of the frontal bone, and then
inward across this latter to the fronto-ethmoidal suture. The
separated portion of the frontal bone measures I.o cm. in
maximum width and a little over 2.0 cm. of surface length,
measured ventrally. There are no radiations, and the division
has the characteristics of an Ordinary suture. There is no
connection between this and the inferior parietal division on
the same side.
The surface of the right parietal shows a slight, irregular
unevenness in the middle, and some fine roughness along the
superior horizontal and the vertical divisions. There is no
depression in the bone. (P1. XIX.)
Judging from the similarity of the divisions on the two
sides, the vertical and superior horizontal sutures on the right
side may quite safely be considered as true anomalous sutures.
The wide and quite deep angle in the border of the parietal
bone from which begins the cleft which is prolonged back-
ward as the inferior horizontal suture on the right, favors the
assumption that this division, also, may be a true anomalous
one. The origin of the shorter division over and beyond the
3O4 Bulletin American Museum of Matural History. [Vol. XIX,
middle of the right parietal I am inclined to attribute to some
violence, though this opinion is based rather on the very
unusual character of the divisions than on any reliable signs
of an injury.
The suture in the frontal bone, equally as the incisure in
the same on the left, is difficult to explain. There is no record
of any similar observations, nor have I seen any other case of
like nature, nor can we explain it from what we know of the
development of the frontal bone. The divisions may possi-
loly be secondary (tension) effects of the anomalous sutures,
or, if the skull has suffered an injury, be the direct results of
the same, their location being influenced by that of the pre-
existing anomalous divisions.
The surface measurements of the two parietals show the
right one to be the larger, in both the antero-posterior and
vertical directions:
Squamo-coronal junction to bregma. . . . . . . . . 1eft 4.4, right 4.7 cm.
{ { { % “ to asterion. . . . . . . . . “ 4.5 “ 4.4 “
Asterion to lambda . . . . . . . . . . . . . . . . . . . . . . . . “ 3.05 “ 3. I5 “
Antero-posteriorly at middle. . . . . . . . . . . . . . . . “ 4.75 “ 5. I5 “
Infero-superiorly “ “ . . . . . . . . . . . . . . . . “ 4.45 “ 4.6 “
Case 49. Cebus, sex unknown, adult (basilar suture Oc-
cluded, second dentition complete); No. 16288, A. M. N. H.,
N. Y.
The left parietal bone shows a now incomplete oblique, the
right an incomplete vertical, and a trace of an oblique
division. *
The division on the left runs from the upper fifth of the
anterior border of the parietal downward and backward, until
it reaches the temporal ridge, beyond which it is entirely oc-
..cluded. Upon close examination, the remainder of the divi-
sion can be traced, particularly ventrally. It runs with a
marked double curve from the ridge downward and a little
backward to a point slightly anterior to the middle of the in-
ferior border of the parietal. At a point o.9 cm. from its
anterior origin, the division is met by a o.2 cm. long branch,
Bulletin A. M. N. H. Vol. XIX, PL. XIX.
MACAcus RHEsus (No.
102, MoRPHoLogical MUSEUM, CoLUMBIA UNI-
versity).
Showing A PARIETAL AND A PARTIAL TEMPORAL Division.

-
Bulletix A. M. N. H. Vol. XIX, PL, XX.
FIG. 2.
Fig. 1.-CEBUs (No. 16,288, A. M. N. H.), BILATERAL Division of THE PARIETAL.
Fig. 2.-FELIS PARDALIs, FEMALE (No. 11,039, A.M.N.H.). Showing A PARIETAL Divisiox.

1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 305
the prolongation of which forward would reach the anterior
border of the parietal a little above its middle; at about this
point we find a small oblong foramen in the border. It is
apparent that originally the parietal suture began at the sum-
mit of a deep and broad cleft. This cleft became filled with
a separate bone, and the larger part of the suture between
the lower border of this and the antero-inferior portion of the
frontal bone became subsequently occluded. In fact, the
separate piece is still completely isolated on the ventral sur-
face of the parietal. The separate bone itself shows in middle
a small, irregularly oval defect, filled with a secondary ossicle.
On the right side the vertical anomalous division begins
superiorly a little beyond the middle of the sagittal border of
the parieta1 (1.9 cm. from bregma, I.7 cm. from 1ambda), runs
I.5 cm. downward, nearly parallel with the coronal suture,
and then becomes obliterated. Posterior to and a little above
the lower extremity of this there is a o.6 cm. long, partly
occluded segment of a division, directed downward and back-
ward. The coronal border of this parietal bone shows two
short incisures, one o.9 cm. and the other 2.3 cm. below the
bregma. (P1. XX, Fig. I.)
The skull as a whole is fairly symmetrical and without any
signs of injuries or other anomalies. The left parietal bone is
slightly higher anteriorly and posteriorly than the right one,
but somewhat lower in the middle; the left parieta1 is also
slightly shorter in its inferior two thirds than the right one.
Surface measurements of the two parietals: -
Inferior end of coronal suture to bregma.... . .1eft 4.8, right 4.65 cm.
Infero-superiorly at middle. . . . . . . . . . . . . . . . . “ 4.5 “ 5.o “
Asterion to lambda. . . . . . . . . . . . . . . . . . . . . . . . ‘‘ 2.8 “ 2.6 “
Inferior end of coronal suture to asterion . . . . “ 4.65 “ 4.8 “
Antero-posteriorly at middle. ... . . . . . . . . . . . . “ 5.05 “ 5.1 “
Case 5o. Cebus albifrons, male, young; No. 5050 A. M.
N. H., N. Y.
The skull shows some generalized pathological condition,
possibly rachitis. The bones contain an excess of organic
matter, and the superior parts of the frontal and parietal
[%une, 1903.] 20
306 Bulletin American Museum of Matural History. [Vol. XIX,
loones show many small indentations of surface and consider-
able pigmentation.
Each parietal presents a posteriorly somewhat incomplete
* division, run -
ning para11e 1
with the squa-
----- ... mous suture. In
addition, the
Sagittal portion
of the right par-
ieta1 is divided
by a vertical fis-
St!Te.
Fig. 26. Ceòzes ałóż/rons (No. 5050, A. M. N. H.), showin
diščºf th:#ffiš.” * g The antero-
posterior divi-
Sions, more clefts with irregular borders than sutures, begin
each about I.o cm. above the lower extremity of the coronal
suture, run across more than two thirds of the bone, and be-
come occluded as they near the mastoid angle; if prolonged in a
straight line, they would terminate in the border of this angle.
The vertical division begins superiorly o.8 cm. from 1ambda
and 2.2 cm. from &
bregma ; it is
patent for 1.6 cm.
and runs nearly ... ----->
parallel with the
1ambdoid suture.
Case 51. Cebus
hypoleucus, male,
young; No. 1 Io 37,
A. M. N. H., N. Y.
The skullis much Fig. 27. Ceòus hy?oleucus (No. 11,037, A. M. N. H.), show
p ig Imented a n d ing an antero-posterior division of the left parietal.
shows signs of a generalized pathological condition, possibly
rachitis. -
Each of the parietal bones shows a horizontal, posteriorly
slightly incomplete (occluded) division. Each division is in
the form of a narrow cleft with irregular borders, and with



1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 3O7
incisures radiating into these borders.
The axis of each of
the divisions runs parallel with the squamous suture of the
same side. The left division begins o.8 cm., the right 1.1 cm.
above the lower end of
the coronal suture.
The left parieta 1
shows also a o.7 cm.
long fissure, which
passes from the lamb-
doid suture directly
above the asterion
toward the parieta 1
eminence. -
The horizontal divi-
sions are very similar
to those observed in
Cebus albifrons, No.
5050, A. M. N. H.
The skull is sym-
netrical, the parietals
nearly equal. No signs
of injuries, or other
anomalies.
Case 52. Ateles, sex
unknown, young; No.
59, M. D., C. U., N. Y.
The right parietal
bone is completely di-
vided by an irregular
vertical cleft-suture,
while the left parieta1


R.
Fig. 28. A teles (No. 59, Morphological Museum,
Columbia University). Parietal division.
shows a small anterior and a large posterior cleft-fissure both
of which run antero-posteriorly, nearly parallel with the
Squamous suture.
The division on the left begins sagitally near a point be-
tween the middle and posterior third of the superior border of
the parieta1 (1.8 cm. from bregma, o.85 cm. from 1ambda). It
runs downward and slightly forward to beyond the eminence,
3O8 Bulletin American Museum of Natural History. [Vol. XIX,
after which it bends and runs backward to within o.5 cm. of
the border of the temporal bone, when it bends again and runs
forward and downward to the inferior border of the parietal.
It meets the temporo-parietal suture slightly posterior to its
middle. There are several oblong openings in the course of
this division, and its lowest portion shows some occlusion.
In the anterior portion of the lower fourth of the right
parietal bone is a o.2 cm. long horizontal fissure.
The anterior division in the left parietal is o.25 cm. long and
directed backward and downward; it is situated o.5 cm. above
the anterior point of the sphenoidal angle. The posterior divi-
sion or cleft begins distally slightly below the middle of the
occipital border of the parietal, is 1.35 cm. long and directed
forward and very slightly downward, running almost parallel
with the squamous suture.
The skull is quite symmetrica1. The bones are all very thin
in spots. Temporal ridges indistinct. The left parietal bone
is somewhat higher than the right one, while the length of the
two is nearly the same.
Infero-superiorly at middle. . . . . . . . . . . . . . . . . left 4.8, right 4.65 cm.
Antero-posteriorly at middle. . . . . . . . . . . . . . . . “ 4.7 “ 4.7 “
TV. RáSUME.
Numbers. — Among the 391 Old World and American
monkeys examined by me 52, or 13.3 per cent., show some
form or other of anomalous parietal division. According to
the species of the monkeys, the proportions of cases with
division are as follows:

Complete Divi- Incomplete
sions, alone or in Divisions No Divisions.
combinations. alone.
29 Cynocephali. O 2 (6.9 %) 27 (93. I 9%)
43 Cercopitheci.. I (2.3 %) O 42 (97.7 %)
Old World 3 Chlorocebi... . O O. 3
Monkeys 7 Cercocebi. . . . . O O 7
I Colobus. . . . . . O C I
Igo Macaques. . . . I5 (7.89 %) 17 (8.95 %) | 158 (83. I6 %)
Total. ... . . .273 16 (5.86%) 19 (6.96%) || 238 (87.18%)
39 Cebi. . . . . . . . . O 9 (23. I 9%) 3o (76.9 %)
sº 41 Ateles........ I (2.44 %) 6 (14.6%) 34 (82.9 %)
American 2 Mycetes. . . . . . O O 2
Monkeys 5 Alouatas. . . . . O O 5
I Nyctipithecus. O O I
3o Hapale. . . . . . . O I (3.3 %) 29 (96.7 %)
Total. ....... II.8 I (o. 84 %) |_I6 (13.56%) || IoI (85.6 %.
Grand Total 391 17 (4.35 %) 35 (8.95 %) | 339 (86.7 %)
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 3O9
—u-
Among the 17 previously reported cases of monkeys with
complete or incomplete parietal divisions, there are 13 Old
World (I Cynocephalus," 8 Cercopitheci, 3 Macaci, and I
Semnopithecus) and 4 New World monkeys (2 Cebi, I Mycetes,
I Arctopithecus = Hapale).
The Old World monkeys show in general a considerably
larger proportion of complete, but a smaller proportion of
incomplete, divisions than the American ones. If we count
all the divisions together, their proportions in my two series
of cases (there are no data as to the number of cases examined
in other instances) are almost equal (12.8% in the Old World,
I4.4 % in the American monkeys); but such a combination
and comparison are not fully justifiable: they would imply an
equivalence of the divisions which cannot thus far be clearly
proven.
The proportion of the anomalies under consideration differs
quite markedly in the various species of monkeys. Divisions
of various nature are comparatively very frequent in the
Macaques, particularly the Macacus rhesus, and quite frequent
in the Cebi and Ateles, but rare in the 1argest and smallest
nonkeys inspected, namely, the Cynocephals and Marmosets.
Age. — With a few exceptions all the instances of parietal
division in monkeys were found in the young or adolescent
animals; even in these cases, however, the anomalous divi-
Sion was often seen to present greater or 1esser signs of occlu-
Sion, thus showing a lesser stability than that of the regular
Sutures. There is no example in the monkeys of a whole or
even a part of an anomalous parietal suture persisting after Oc-
clusion has much advanced in the normal parietal articulations.
Sex. — Contrary to what is found in man, in monkeys the
females are well represented among the individuals with parie-
tal divisions. In fact, they surpass the males in a proportion
of 2 to I in the category of complete sutures, but are in turn
surpassed by the males, in nearly the same proportion, in the
class of incomplete divisions. Counting all the divisions, the
proportions of the same in the two sexes are very nearly
.* Maggi (63) mentions another case of parietal division in a “Papio Mormon,” but
gives in that place no particulars.
3 IO Bulletin American Museum of Matural History. [Vol. XIX,
equal. It is not impossible that the smaller proportion in the
males of complete, and a larger one of incomplete, divisions is
due to the fact that in the majority of the male skulls with
the anomaly, obliteration of the anomalous sutures has from
Some cause advanced further than was the case in the major-
ity of the female skulls with parietal divisions.
The coincidence of unequal proportions of the anomalous
divisions when separated into complete and incomplete ones,
and the equalization of these proportions when such a dis-
tinction is abandoned, in the case of the males and females as
well as that previously considered of the Old World and
American monkeys, is remarkable and opens an interesting
little field for further investigation.
The following table gives the details of the proportions of
the complete and incomplete divisions in my cases, in the two
SeXeS .
OLD WORLD MONEEYS.

Complete Divi- i-
sions (between
Number any two borders | Incomplete Di- No
Examined. of the parieta1), visions, alone. Division.
alone or in com-
binations.
Cynocephali.
Males. . . . . . . . . . 2 O 2 O
Females. . . . . . . *- *- *- -
Sex unknown... 27 O O 27
(29) (o) (2) (27)
Cercopitheci.
Males. . . . . . . . . . - - - *
Females. . . . . . . I I * O O
Sex unknown... 42 - O O 42
(43) (I) (o) (42)
Chlorocebi, Cercocebi, Colobus.
Sex unknown...] I I | o | o ! II
Macaci : M. rhesus.
Males. . . . . . . . . . 35 3 (8.57 %) 2 (5.73 %) 30 (85.7 %)
Females. . . . . . . 3 I 4 (12.9 %) 2 (6.4 %) 25 (8o. 6 %)
Sex unknown... 64 7 (Io. 9 %) 9 (14. I 76) 48 (75. o 9%)
(130) (14) (I3) (Io9)
M. Cynomolgus.
Males. . . . . . . . . . - *- *-*. *-*
Females. . . . . . . I I C O
Sex unknown. . Q O O Q
(Io) (I) (o) (9)
M. erythraeus.
Sex unknown...! 8 O | 3 (37.5%) 5 (62.5 %)
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 3 II

Complete Divi-
sions (between
Number any two borders | Incomplete Di- . No
Examined. of the parietal), visions, alone. Division.
alone or in com-
binations.
M., various undetermined species.
Males. . . . . . . . . - - --> -
Females. . . . . . . I O O I
Sex unknown... ſº 4. I O I 4O
(42) (o) (1) (41)
Total of Macaques.
Males. . . . . . . . . . 35 3 ( 8.57 %) 2 ( 5. 73 %) 3o (85.7 %)
Females. . . . . . . 33 5 (I5. I5 %) 2 ( 6. oé 96) 26 (78.8 %)
Sex unknown. . I 2.2 7 ( 5.7.47%) I3 (Io.65%) Io.2 (83.65 %)
(190) (15) (17) (158)
AMERICAN MONKEYS.
Cebt.
Males. . . . . . . . . . I O I O
Females... . . . . . 4- - - -
Sex unknown... 38 O 8 3O
(39) (o) (9) (3o)
Ateles.
Males. . . . . . . . . . I 2 O I 2 O
Females. . . . . . . - 4- -s am-
Sex unknown. . 38 I 3 34
(41) (1) (6) (34)
Hapale.
Sex unknown...] 3O O I | 29
Mycetes, Alouatas, Nyctipitheci.
Sex unknown...] 8 | o O | 8
TotALs.
g
5.5 Complete Di- || Incomplete Total of
* = | visions, alone Divisions, 9tal ºf Cases | No Divisions.
É : or with others. alone. with Divisions.
Zſº
Males....... . . . 41 || 3 (7.3 %), 7 (17.1 % Io (24.4 % 31 (75.6 %)
Females. . . . . . . 35 6 (17. I4 %) 3 ( 8.57 % 9 (25.7 % 26 §: %3
Sex unknown...] 315 8. ( 2.54 %) 25 ( 7 - 94 %) || 33 (Io. 48 %) 282 (89.5 %
(391) (17) | (35) (52) (339)

The sex was not reported in any of the previous 17 records.
Direction. — Among the total 69 monkeys with parietal
divisions now on record, including the above, there are 36 in
which the anomaly is bilateral and 32 in which it is unila-
teral; or, counting the separate parietal bones, there are, out
of a total of 138 of these, Io 5 with, and 33 without, divisions.
31 2 Bulletin American Museum of Natural History. [Vol. XIX,
The total number of individual divisions amounts to I33,
and of these there are:
15 instances of complete vertical (infero-superior) suture;
& &
5 I incomplete. “. g e *
3 & 8 & & comp; division running from the sagittal suture to the mastoid
angle;
4. & 4 “ incomplete division running from the Sagittal suture to the mas-
toid angle; "
Total, 73 instances of more or less vertical divisions.
4 instances of complete antero-posterior suture;
4.O & 4 “ incomplete ‘ 4 &
Total, 44 instances of more or less horizontal divisions.
8 instances of complete oblique suture;
8 & & ‘ incomplete “ £ &
Total, 16 instances of oblique divisions.
The previously published observations on monkeys, in-
cluded in the preceding Summary, comprise 6 complete and
8 incomplete vertical, 2 complete and 7 partial horizontal, I
sphenoidal angle-lambda, I sphenoidal angle-Sagittal suture,
I middle of coronal to middle of Sagittal suture, and I Supe-
rior part of coronal to inferior part of lambdoid suture divis-
ions. Altogether we have then in monkeys, known to date,
73 instances (55. 96) of more or less vertical,
44 tº & 33. Z, ) . . . “... “ , horizontal, and
I 6 & 4 12. 9%) “ oblique divisions.
The preponderance of the vertical over all other divisions is
very evident, and constitutes one of the most interesting re-
sults of my examinations. We will return to these data in
the succeeding chapter.
Location. — Among the Ioë parietal divisions in my 52
cases, 56 (33 vertical, I 7 horizontal, 5 oblique) are on the
right and 5o (26 vertical, 18 horizontal, and 6 oblique) on the
left side; which is a pretty even distribution. Among the pre-
viously known 27 divisions I 5 were on the right, II on the
left side, and I ? The total: 71 instances (53.9%) in the
right and 61 instances (47.9%) in the left parietal. The differ-
ence in the two sides is too small to be of much significance.
Of the incomplete vertical divisions a very large majority
is found in the Superior portion of the parietal, and particu-
larly in the posterior four fifths of this portion.
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 3 I 3
Of the 4o incomplete horizontal divisions, 25 are in the an-
terior and 14 in the posterior portion of the parietal bone, (IP),
and communicate respectively with the coronal and lambdoid
Sutures.
Of the minor oblique divisions, 2 separate the tip of the
sphenoidal angle; I runs from the posterior to the inferior bor-
der; and I is situated in the anterior, I in the superior, 3 in
the postero-superior, 3 in the posterior, and I in the postero-
inferior portions of the parietal. &
Size of the Parietals. – Where both parietal bones are
divided in a similar manner, the size of the two bones is gen-
erally very nearly equal; where the division is unilateral, or
bilateral but dissimilar, the size of the bones generally dif-
fers. The presence of a division is probably, as a rule, a
feature favorable to the growth of the bone with the anomaly,
particularly to a growth in the direction at right angles to the
division, which agrees with the well-known law of growth
of the bones under similar circumstances in man. There is
noticeable in the monkeys a lesser regularity and lesser promi-
nence of the differences in growth than is usually found in
man; this is undoubtedly partly due to the smaller dimensions
of the bones in the monkeys and partly, probably, to a fre-
quent earlier presence of a bilateral division.
The following table shows the relative proportions of the
parietals in which but one parietal showed a division:


Case. Parietal Nature of Right Parietal Right Parietalis
No. Divided. Division. Exceeds in: smaller in:
29 left incomplete infe- hight, length at length, inferiorly
rior vertical middle e
36 left incomplete pos- length bight, especially
terior horizontal posteriorly
3 right incomplete supe- length hight
rior vertical &
24. right incomplete infe- length, hight flight posteri-
rior vertical anteriorly orly
26 right incomplete infe- length, hight *º-
rior vertical
IQ right vertical (partly length, hight wº-º-º:
occluded) e
I4. right incomplete ver- hight 1ength at middle
tical slightly .
28 right incomplete infe- length, hight hight posteri-
rior vertical at middle orly
44 right incomplete hori- 1ength *=
zontal and in-
complete vertical
3I4 Bulletin American Museum of Matural History. [Vol. XIX,
Asymmetry. — While minor irregularities in form, determin-
able mostly only by measurements, are common in monkeys with
parietal divisions, the more marked asymmetries, amounting
to plagiocephaly, such as occur very frequently under similar
circumstances in man, are very rare. Here again we must
consider the naturally Small size of the monkey parietals on
which asymmetries are less visible than on the considerably
larger human bones. It is very probable, however, that in
man there is felt more than in monkeys the influence of an
additional factor in producing an excess of growth in the di-
vided parietal, and thus leading to asymmetry of the cranial
vault, which factor is the more rapid and longer continued
brain growth.
Pathological. — The monkey skulls with parietal divisions
which I examined are almost absolutely free from pathologi-
cal conditions. The only exceptions to this are the skulls of
two young Cebi (Cases 50 and 51), which show what is prob-
ably a generalized rachitic condition. Hydrocephalus is a
condition that is either absent or excessively rare in monkeys,
and no one of the specimens with divisions shows the slightest
traces of it.
Intercalated Bones; Early Normal Divisions. – There is no
indication that intercalated bones, comparatively rare in
monkeys in general, are more frequent in the skulls with
divided parietals; and the same may be said of metopic and
other earlier normal sutures. Not one of my specimens with
a parietal division, and only one of those described by others
(Cercopithecus, Coraini), has a fully preserved metopic suture,
though one or both terminal portions of the same are common
in the younger subjects.
Characteristics of the Anomalous Divisions. – The complete
or longer parietal divisions in monkeys show generally more
or less the character of a suture. Many show more or less of
a serration, which usually approaches in type that of the
regular sutures. Besides the superficial serration, the divi-
Sions show often a tendency to a squamous arrangement, and
some are distinctly of a squamous nature. Among these in
cases 18, 21, 22, 25, and 46, the border of the anterior over-
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 31.5
lapped that of the posterior; in case 47 the border of the
posterior overlapped that of the anterior; and in cases 47 and
31 the border of the inferior overlapped that of the superior
portion of the divided bone.
Occlusion. — As a general rule, to which there may be some
exceptions, the anomalous parietal divisions in monkeys tend
to an earlier synostosis than the normal articulations of the
parietal. They are also affected by a relatively earlier synos-
tosis than is the case with similar divisions in man, which
probably stands again in connection with the differences in the
growth of the brain.
The preceding data show, in the main, that anomalous
parietal divisions are much more common in monkeys and
apes, particularly in certain species, than they are in man;
that they occur with about the same frequency in both sexes
and offer a much greater variety than in man; that divisions
of a certain kind, particularly such as run more or less parallel
with the coronal and lambdoid sutures, while extremely rare
in man, are quite common in the monkeys; that the divisions
in the monkeys give rise to relatively 1esser deformities of the
cranial vault and are subject to a relatively earlier occlusion
than those in man; and that pathological conditions of
the skull play apparently no rôle in the production or Susten-
ance of the divisions in monkeys; all of which conditions are
undoubtedly of some importance in the study of the phe-
nomenon of parietal divisions in general.
W. PARIETAL DIVISIONS IN MAMMALs Low ER THAN THE
Mon KEYS.
In more than two thousand adolescent and adult crania of
various mammals lower than monkeys, which I inspected
within the last six years, I found but one with a major, and
two with minor, complete parietal separations. These will be
the first cases on record, which is proof of the great rarity of
this sort of anomalies in the parietal bone in adolescent and
adult mammals below the monkeys.
316 Bulletin American Museum of Natural History. [Vol. XIX,
The major separation consists of a complete vertical-
oblique suture in the right, and an incomplete similar suture
in the left parietal of an adolescent ocelot. The minor cases
are a separation of a portion of the mastoid angle of one of the
parietals in a puma, and a separation of a portion of the
Sphenoidal angle in a seal and a deer. In detail these cases
are as follows:
Felis pardalis (No. IIo39, A. M. N. H.), male, adolescent.—
The skull shows no signs of injuries and no anomaly besides
the parietal divisions. No Wormian bones.
Both parietals are affected by what is apparently an anoma-
1ous division. Both divisions begin at the same point from
the Sagittal suture, I.6 cm. posteriorly to the bregma and 2.2
cm. anteriorly to the lambda.
On the right parietal the anomalous suture passes from the
Superior border at first for 1.3 cm. downwards, and then, after
a bend, downward and forward, to end in the posterior ex-
tremity of the sphenoidal border of the parietal, directly oppo-
site the temporo-sphenoidal suture. The anomalous suture
shows on both sides a moderate serration and is patent.
On the left parietal the division is incomplete. It pro-
ceeds for 8 mm. nearly paralle1 with the vertical axis of the
bone, after which it becomes much less distinct, curves slightly
forward, and is lost near the well-marked temporal ridge.
(P1. XX, Fig. 2.)
Measurements of the two parietals show the following differ-
€11CeS :
Antero-posterior arc at middle. . . . . . . . . . . . . . left 3.8, right 3.6 cm.
{ { 6 & “ temporo-sphenoidal point
to asterion . . . . . . . . . . ... • - - - - - - - - - - - - - - - - “ 2.6 “ 2.55 “
Hight, temporo-sphenoidal point to bregma... “ 3.4 “ 3.65 “
“ at middle. . . . . . . . . . . . . . . . . . . . . . . . . . . “ 3.3 “ 3.15 “
“ asterion to lambda. . . . . . . . . . . . . . . . . . “ 2.35 “ 2.35 “
The left parietal, according to these measurements, is
slightly longer and higher at middle than the right parietal,
this latter being higher anteriorly. The actual area of the
two bones does not show much difference, and the skull is
not appreciably asymmetrical.
1903.] Hrdlička, Parietal Bone in Man and other Mammals. 3 I 7
There are, as already mentioned, no signs of injuries on
the skull. The normal sutures show the first traces of Ossi-
fication.
Felis concolor (No. 5034, A. M. N. H.), adolescent, sex un-
known.— The right parietal bone shows a separation of a
portion of its postero-inferior angle by a 1.5 cm. long, slightly
Serrated Suture, running straight between the posterior and
inferior parietal borders. No other anomalies, no signs of in-
jury. No intercalated bone or a separation in same location
in 14 other pumas.
Dorcelaphus hemionus (A. M. N. H.), adolescent, sex not
determined. — The right parietal shows a separation of the
extremity of its sphenoidal angle. Nothing similar in Io
other Dorcelaphi, but a slightly incomplete separation of like
nature in a Phoca jaetida.
There are in the American Museum numerous skulls of
various species of South American rodents of the genera Cte-
nomys and Lagidium, every one of which skulls presents at the
asteric angle a comparatively large, regular, quadrate (more
often) or triangular bone. This bone, which apparently is
characteristic of these species, is either a regular fontanel bone
or a separation of the postero-inferior angle of the parietal.
The former of these suppositions seems more probable, but
the point can only be settled by further observations, par-
ticularly on the young of the species.
For fissures in the parietal bone in mammals below the
monkeys v. detail chart at the end of the chapter on ‘Divi-
sions to Foramina.”
VI. PATHoLog ICAL AND AccIDENTAL DEFECTS AND DIVISIONS
IN THE PARIETALS.
This category of cases will be noticed only because some of
the defects and divisions present at times forms which it is
difficult to distinguish from the normal or anomalous parietal
separations.
The pathological defects in the parietals occur as irregular,
1arge perforations; smaller rounded or oval perforations; and
318 Bulletin American Museum of Natural Hisſory. [Vol. XIX,
circular or oblong foci, which, sieve-like, are full of minute
perforations or pores. The proper diagnosis of these defects
can but rarely present much difficulty; they may, however,
coexist with other divisions and be separable with less facility.
Effects due to mechanical influences appear on the parietal
bone as simple or radiating fissures, and as more or 1ess com-
plete and suture-like, simple or branching, lineal, or, much
more commonly, irregular separations. In Some of these
cases a differential diagnosis of the division from a normal
or anomalous fissure or suture is very difficult and may be
impossible. The circumstances which in doubtful cases
would favor the recognition of a division or a fracture are
(already partly mentioned when the very oblique and infero-
posterior sutures were considered): signs of a cranial injury,
especially when in connection with the division; irregular
course, branching, one-sidedness, incompleteness, and a very
unusual location of the division; and its extension into
neighboring bones. As contributive signs of secondary im-
portance in favor of a fracture may be considered an absence
in the division of Wormian bones, separation of the borders
of the bone along the division, bluntness of the borders, and
callus formation. No one of the above signs of differentia-
tion is alone decisive, and with all of them in mind we will
still meet with cases which shall baffle our efforts at a distinc-
tion of the division. The following instance shows a fracture
of the parietal which, though recognizable, offers nevertheless
a considerable similarity to a Sagittal parietal suture.
Case a. Cercopithecus fuliginosus, nearly adult; No. 2065,
A. M. N. H., N. Y.
The lower part of the squama of the frontal bone on the
right side shows the signs of a considerable injury. Appar-
ently the bone was fractured, and two pieces, the Superior of
which was quite large, were separated, but have since reunited
together and with the frontal bone. One of the breaks ex-
tended forward to the temporal ridge. The superior wall of
the orbit shows two larger and several pin-point defects. The
fronto-parietal articulation on each side appears as if it had
been forcibly spread, and the coronal suture extends straight
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 3 I 9
downward, separating the anterior extremity of the tem-
poral squama on the left and a portion of the wing of the
sphenoid on the right. The surface of the sphenoid and tem-
poral bone, below the termination of the prolongation of the
coronal suture on the right side, shows fine superficial porosity.
Besides the thus far mentioned effects of the injury we see
on the right side a temporal and a parietal division. The
temporal division begins at the extended coronal suture, I. I
cm. below the squamo-coronal junction, and, passing back-
ward and upward, terminates a little posterior to the middle
of the squamous border. Though plainly traceable, this divi-
Sion is well on the road to occlusion.
The parietal division begins 1.1 cm. above the squamo-
coronal junction and o.2 cm. above the external mark of the
superior fracture of the frontal bone. It runs downward and
lbackward to within o. 55 cm. of the squamous suture, and then
almost directly backward to a point o.4 cm. above the aster-
ion, terminating a short distance anterior to the lambdoid
suture. The division is not squamous nor serrated; the
borders of the two portions of the parietal bone lie simply in
apposition. Parts of the division show occlusion and very
slight superficial signs of inflammation (roughness, deposition
of new bone, fine porosity).
In the Superior portion of the right coronal suture, o.25 cm.
from bregma, is a quite large Wormian bone, formed almost
entirely at the expense of the parietal.
The skull is symmetrical. The right parietal bone is higher
anteriorly and at middle, but lower posteriorly, than the left
one, while the length of the two is very nearly equal. The
parietal division, other lesions excluded, could very easily be
taken for an anomalous suture. (P1. XXI.)
VII. THE CAUSES OF ANoMALO US PARIETAL DIVISIONS.
The original condition which makes the “typical” com-
plete anomalous division of the human parietal bone possible
is, as is to-day probably generally acknowledged, the existence
of more than one center of Ossification of the bone. These
32O Bulletin American Museum of Matural History. [Vol. XIX,
Centers, which ordinarily unite and form one bone, persist in .
rare instances in their separation and give rise to a parietal
Composed of two or more portions, similarly as happens some-
times in the human malar.
The theory of the development of the parietal bone in man
regularly from two centers, and the ensuing elucidation of the
Origin of the typical parietal division on this basis, is due almost
entirely to the researches of Toldt (1882–83) and Ranke
(1899). Before Toldt it was a generally accepted opinion
that the parietal bone develops from one center, and the
origin of a parietal suture was a matter of speculation. Soem-
mering (8) recognized it to be of congenital origin. Certain
expressions of Hyrtl (50), Gruber (25, pp. 12–15), and even
Welcker (17, p. Io9) make it probable that all these observers
suspected that the original cause of the divided parietal is a
presence of a double center of ossification of the bone, but
neither author has made a definite statement on that point.
In fact Welcker later on, as already mentioned (55), declared
a development of the parietal from more than one center in-
admissible. Hyrtl, in particular, reflected more upon a rela-
tion between the temporal ridges and the parietal suture than
On that between this and a greater number of the centers of
Ossification. Calori (20, p. 341) attempted to explain the
divisions in the cases that came under his observation by the
theory that in the apparently divided parietals the additional
portion of the bone was developed from an accessory portion of
the Ossifying parietal that became isolated and failed to unite
with the real center of ossification because of an abnormal dis-
tention of the cranial vault." Coraini, considerably later (1893)
and after Toldt's work, advanced, partly in agreement with
Calori's view, the hypothesis that in the apparently divided
parietal one portion of the bone is the real parietal and the
Other is an accessory one, closely allied in nature with the
Wormian bones (33, pp. 140–144; v. following foot-notes).
* “Quindi la circonferenza esterna, o 1'inferior-anteriore del germe osseo dei parietali
non potendosi assimilare la sostanza ossea depositantesi al di fuori di lei, e rimanendo
tale Sostanza sciolta e libera e dilungandosi per la distensione via via crescente dal germe
cui doveva servire ad augumento, resasi indipendente ha fato disé centro di ossificazione
a sé stessa, e si è costituita in osso distinto, separato dal germe osseo proprio a parie-
tali,” etc.; v. also the following foot-notes.
BULLETIN A. M. N. H. Vol. XIX, PL. XXI.
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CERCOPITHECUS FULIGINOSUS (No. 2065, A. M. N. H.). PARIETAL SUTURE
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1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 32 I
Maggi and Frassetto, finally, advanced, as already men-
tioned in the introductory chapter, the theories of respectively
three- and four-center Origin of the parieta1.
Toldt's investigations concerned the regular development of
the normal human parietal bone, and the explanation of the
formation of a divided parietal was an inference based on
the results of that research. The author expresses himself in
the following language (48): “The Ossification of the parietal
begins in the Ioth week of the embryonal life. It commences
in the form of a wide-meshed net, composed of slender laminae
of bone. During the IIth to 13th week this net shows the
formation of two, superimposed, more dense centers. The
1aminae of bone radiate from each of these centers and meet
on the opposed portions of the periphery of the two sets. In
Some cases the radiate arrangement is less pronounced in one
than in the other center. Both centers unite gradually during
the 4th month, nevertheless their former separation is still
marked by a more or less deep anterior and posterior cleft in
the bone. In the 5th month the development of the parietal
eminence takes place, in the situation where the two centers
have met. There are, in consequence, in opposition to the
commonly accepted opinion, two well-distinct, even if not
completely separated, points of Ossification for the parietal
bone. This makes it possible to explain the occasional sagit-
tal suture in the parietal bone.”
In 1883 (49) Toldt supplemented the above statement by
further explanation and by an illustration, showing a case
with two clearly marked, though not fully separated, parietal
CenterS. º
Since Toldt the theory of a two-center development of the
divided as well as the undivided parietal has been gaining a
gradual recognition (Putnam, Turner, Coraini, Dorsey, O. .
Schultze, Graf von Spee) until 1899, when it received an im-
portant corroboration by the work of Ranke (36). Before
the work of this author, however, there appeared in 1896
and 1897 (59, pp. 9oo, 9or, and 6o, p. II65 et Seq.) the contri-
butions of Maggi, who declared, basing his conclusion on his
observations on human foetuses, that the human parietal
322 Bulletin American Museum of Natural History. [Vol. XIX,
develops from three centers, but that even four centers of Ossi-
fication may be encountered. Of the three centers two
may fuse early and leave but two separate. The formation
of these different centers is posterior to that of the unique
center that appears about the 45th day of foetal life. Accord-
ing to this the Ossification of the parietal would start about the
6th or 7th week of intrauterine life from one focus, but a little
later on there would appear two, or more rarely three, addi-
tional centers. Thus far this theory has not been sub-
stantiated by any other author, though it is utilized by
Frassetto; but it must be remarked that, with the exception
of Ranke, no author since Maggi has made any extensive
embryological inquiries into the matter.
Ranke's researches extended over some embryological ma-
terial on which he found no such centers as announced by
Maggi (he does not mention Maggi’s work), but conditions
similar to those announced by Toldt, that is, an early and
usually brief, but apparently regular, existence of two foci
of Ossification for the parietal. Following with investigations
on older subjects, Ranke shows that more or less marked traces
of the original two portions of the parietal are, in man, com-
mon at birth, and can occasionally be detected even much
later in life; and that similar, only still more marked and
1onger-lasting signs of a similar condition can be seen on the
skulls of apes, particularly the Orangs.
But Ranke's conclusions also differ in several details from
those of Toldt. In Ranke's words (36, p. 52): “My tests of
Toldt's teachings have resulted in a complete agreement in
the main points of our observations. There is, however, one
point in which I must go further. I find that we have not
simply ‘two to a certain degree independent centers of Ossi-
fication,’ but that: The human parietal bone is a complex of
two embryonal, separated, Superimposed, elementary bones of
* 59, p. 9oo: “I centri di Ossificazione dei parietali, che finora potei chiaramente
vedere in feti umani da 2 mesi e mezzo a 3 mesi e mezzo, sono tre per ciaScun Osso.
Talora di questi tre centri, Sempre in feti dello stesso tempo di sviluppi Suindicato, due
si uniscono"in un solo e si hanno allora soltanto due centri di Ossificazione per parte.
La formazione di questi diversi centri Segue a quella, ammessa dagliantori, di un punto
unico di ossificazione per ciascun parietale, che appare verso il 45° giorno di vita in-
trauterina, e precede quella della gobba parietale.”
* 60, p. 1167: “Quatro centri di Ossificazione per ciascun parietale, che talora si
vedono neifeti umani,” etc.
1903.] H.rdlička, Parietal Bone in Man and Other Mammals. 323
the skull, which unite only during the later progress of develop-
ment.”
“The occurrence of the horizontal division of the parietal
bone results, as established by Toldt, from an individual de-
velopment of the two portions of the bone.” “The parietal is
a complex of two elementary bone-individuals, whose separa-
tion can from certain causes persist just as well, even if less
frequently, as the frontal suture, the embryonal separation of
the two frontals” (p. 56). --
The parietal eminence is “formed from the fused centers of
ossification of the upper and lower parietal,” “and not at the
point of the former dividing line of
the two centers” (pp. 55, 56).
“The form of the parietals shows
in all the new-born, as well as older
products in our race, traces of the
former division of bone by a parie-
tal suture into an upper and a
1ower parietal’’ (p. 29).
The principal observations upon
which Ranke based his conclusions
are as follows (36, pp. 52–56, figs.
29–32): Fig. 29. , Head of a Human Em-
bryo, showing two separate parietal
I. An embryo 6.5 cm. long shows ºrjācāiºn ºr ſº
the upper and lower parietals fully
developed, but still completely separated. (Fig. 29.)
2. An embryo of 9.0 cm. total length shows also a still
complete separation of the upper and lower parietals; but
there appear to be differences in the position and size of the
elementary bones.
3 and 4. In two embryos of respectively Io.o and II.o cm.
length, the two original centra of the parietal bone are united,
lout their existence is still recognizable and traces of their
union are still patent.
5. An embryo of 12.0 cm. length showed similar condi-
tions as the preceding. (Fig. 30.).
These cases show very plainly the formation of the human
parietal from two superimposed foci and there is no trace of

324 Bulletin American Museum of Matural History. [Vol. XIX,
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1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 325
such a condition as is mentioned by Maggi. It is difficult,
however, to accept as demonstrated Ranke's view that these
foci represent or are two distinct parietals, for we meet with
similar foci in all the cranial and facial as well as all the other
bones of the skeleton, and we should have to assign to all a
similar morphological value. We shall return to this view
1ater. The essential point which concerns us in this place,
and which Toldt's and Ranke's investigations seem to estab-
lish, is the real manner of the development of, particularly,
the human parietal bone, which enables us to comprehend the
formation of the anomalous parietal divisions, particularly the
“typical” horizontal parietal divisions.
Frassetto's four-center theory (70) needs scarcely more than
be mentioned; it lacks a proper substantiation.
Toldt's and Ranke's, and we may include Maggi’s, researches
explain the original condition which makes the anomalous
parietal divisions, at least those of a certain sort, possible; the
plain fact of the original existence of two (or even more than
two) separate centers of Ossification does not, however, reveal,
and, in fact, has hardly any relation to, the actual cause or
causes of the persistence of the separation of these centers.
This persistence requires, as Ranke well says (p. 27), “an
additional individual cause, without which such ‘supernumer-
ary’ sutures would not be found in the adult crania.”
What that determining cause or causes may be is still largely
a matter of conjecture. Calori, and after him Coraini,”
* 20, p. 338 et seq.: The parietal bone develops from one unique center of ossification,
and in consequence of that, the mode of formation of a division in the bone must differ
from that of the frontal, squamo-mastoidal, or transverse occipital suture. “Ci possi-
amo però valere delle altri condizioni, cioe dello svilupparsi ed aumentarsi od ampliarsi
del cervello e della capsula cranica o normalmente, o per ipotrofia di esso, ovvero per
idrocefalo, sproporzionatamente allo sviluppo ed incremento delle Ossa. Posto dunque
che il cervello cresca sproporzionatamente, O viabbia idrocefalo, e la capsula predetta
consentendo al contenuto si dilati, dee necessariamente sonseguitare che il processo
ossificante si rallenti si per la compressione come per la diversione di una parte di ma-
teriali nutrizi da esso lui, materialiſche a se attrate il cervello, o l'idrocefalo che cresce a
sue spese. Per questa scarseggiante nutrizione gli spazi membranosi interposti ai
punti di Ossificazione od alle Ossa cheessi compongono, rimarranno molto estesi; an:Zi
siestenderanno vieppiù in forza della distensione. I punti ossei poi crescendo e dilatan-
dosi per 1’aggiunta disostanza ossea alla loro circonferenza non avranno in virtù della
forza distendente molta agevolezza di appropriarsela, anxi ne saranno impediti, per
forma che rimarra ella libera e si dilunghera da essi, e ci apparira, come non di rado,
sotto forma di isolette in quegli spazi membranosi, le quali cresceranno in wormiani, e
radoppieranno le suture, od in forza della sinostosi congiugerannosi e comporrannoi
in un osso solo, che più tardi si articolera per suture con le ossa vicine.” Seq., pp. 34o,
34I.
* 33, p. 142 et seq.: “La causa di questa serie di fenomeni e della divisione quidi dell
parietale ritengo, con Calori, che debba essere considerata una sproporzione fra l'ac-
crescimento del contento cranico e 1'accrescimento delle ossa del cranio, di tal maniera
326 Bulletin American Museum of Natural History. [Vol. XIX,
search for such an influence in a disproportion, due to physi-
ological or pathological causes, between the growth of the
cranial contents, in favor of these, and the cranial, especially
the parietal, bones. The disproportion may be due either to
physiological (rapid growth of brain) or pathological causes
(hydrocephalus). Coraini further sees in the phenomenon a
tendency to an appearance of a new bone, an example of
neomorphism.
Maggi, as already referred to under ‘General Remarks,’
considers the divided parietals homologous with the multiple
parietal scales in stegocephali, etc. This comparison seems to
imply that the anomaly in the human parieta1 is reversive in
Inature.
There is no further expression of opinion on the determin-
ing cause of the parietal divisions except by Ranke. This
author's view, that the two foci from which the parietal
develops represent two independent parietal bones, would
seemingly tend to approach the parietal sutures to examples
of neomorphism. Ranke, however, expresses another theory,
which is as follows (36, pp. 27–28): “It has long since been
established by Virchow that the so-called supernumerary
sutures are very often observed in company with prema-
turely synostosed normal sutures. It can be imagined
that the pressure of the growing brain against the cranial
vault, meeting with an abnormal resistance in the locality of
the premature synostosis, expands more strongly those parts
of the vault, such as bones divided by a suture, at which it
meets with a lesser resistance, and thereby hinders the nor-
mal closure of those foetal sutures and fissures that are still
open. The earlier this normal process of closure in foetal life
tends to be effected, the more rare will be the corresponding
supernumerary sutures in the adult.”
da fare sisentire 1a sua influenza specialmente nell’ ambito dei parietali, i quali per ció
non possono da soli completare la corrispondenta parte della scatola cranica.”
P. 144: If confirmed, “I’anomalia rappresentarebbe dunque un fatto, che potrebbe
dirsi de neomorphismo; rappresentarebbe una variazione che tende a fissarsi e che
porta formazione di un nuovo osso, il parietali accessorio, il quale sarà nei singoli casio
unico o multiplo.”
. P. 144: “Ma in ognisingolo cranio essa potra avere inaltre un altro e speciale signif-
icato, potra rappresentare un carattere di superiorita, nel senso antropologico, qualora
la sproporzione, indicata come causa della sua comparsa, sia dovuta ad un aumento
della massa cerebrale conginuto a superiorità di attivita psichica; oppure rappresentera
un carattere patologico, qualora tale sproporzione sia prodotta da una conditione
patologica.”
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 327
We shall return to most of the just-mentioned theories of
origin and causation of parietal divisions later. What needs
to be remarked in this place is that they all, except those of
Maggi and Frassetto, apply principally to the complete typical
antero-posterior divisions. These are, however, not the only
divisions which occur even in the human parietal." There
have been observed also some very oblique divisions crossing
the whole bone, and others, oblique or angular, which separate
One, usually the mastoid, angle of the bone. About the nature
of these atypical and minor divisions there is considerable un-
certainty. Welcker apparently considered the minor as equiva-
lent with the major sutures. He says (17, p. Io9): “I know a
number of skulls on which can be seen a suture beginning at
the middle of the lambdoidal margin of one of the parietals
and passing over this bone; but this particular suture, instead
Of halving the parieta1, bends towards the temporal border,
separating only the mastoidal angle of the bone. The sep-
arated piece has the appearance of a 1arge intercalated bone.
When the separated lower segment is equally as large as the
upper part, as in a horizontal division of the whole parietal
bone, the term intercalated bone (Schalt oder Nahtknochen)
is not applicable to either of the pieces; yet the process of
production of the two segments, when of equal size, must
have been exactly the same as in the case where pieces of
unequal size have resulted.” Gruber, in describing an in-
stance of a separation of the mastoid angle (25, pp. 12–15)
calls the separate postero-inferior portion a “parietale secun-
darium posterius,” which term gives that portion a similar
morphological value with the 1arger antero-superior bone, and
approaches the suture dividing the two to the typical antero-
posterior anomalous suture. Putnam (26), speaking of the
postero-inferior (as later shown, inferior) segment in his
second Tennessee specimen, considers this as developed from
“a separate center,” which also tends to give the anomalous
suture a similar value to that of the typical antero-posterior
one. For Toldt (49, p. 86) the very oblique antero-posterior
* The material in apes and monkeys being almost wholly very recent must be ex-
cluded from these and following notes; these should be understood to apply solely,
unless specified otherwise, to the human parietals.
328 Bulletin American Museum of Natural History. [Vol. XIX,
sutures of the parietal had the same significance with the
typical horizontal ones, and were due to a preponderance of
growth in one of the centers of ossification. For Coraini, the
divisions that separate only an angle of the parietal bone have
practically the same significance as the divisions that halve
the bone, –they are all accessory bones, allied to the Wormians
formed from accessory centers of the parietal. The restric-
tion of the division to one angle may be explained either by a
later appearance or lesser growth of the accessory center;
or, even more probably, by the supposition that there were
originally two superimposed accessory centers, and possibly
formed portions, as in the case of Fusari, one of which, how-
ever, united early with the main portion of the bone or the
real parietal. The nature of the sutures, transverse, oblique,
or vertical, depends on the relative position of the centers
from which the particular parietal is developed. Maggi,
with his three- or even four-center theory finds naturally an
easy explanation for all forms of division of the parietal; and
so does Frassetto.
For Graf Spee (51), “the typical development of the parie-
tal bone from two centers does not afford any explanation for
those fissures which divide the planum temporale ofthe bone.”
“It is possible that the portions of temporal squama and those
º 33, p. 14o et seq.: “Io penso che la divisione del parietale possa essere intesa nel
modo seguerite: Quando il parietalo sorge anormalmente da due punti di ossificazione,
si potrà avere una delle prime quatro (a, 6, y, è) varietà di divisione dell' osso; si avrà
cioè un parietale bipartito da una sutura soprannumeraria, l'audamento della quale,
trasversale, verticale, o variamente obliquo, dipenderà dalla posizione reciproca occu-
pata dai due germi del parietale al loro insergere e dal vario potere di accrescimento che
ognuno di essi verrà manifestando nella contesa, direi, dello spazio.
“Anche le due successive varietà (e, m) di parietale diviso per separazione dell' angolo
mastoideo pare che possano ripetere il medesimo meccanisimo. Il parietale deriverebe
egualmente da due germi di ossificazione, uno di quali però sarebbe sorto molto eccentri-
camente cioè nell'ambito di uno dei detti angoli parietali, ed inoltre o sarebbe sorto tardi
rispetto al altro, o sarebbe statº dotato di minore attività formativa,
“Senza escludere questa maniera di prodursi delle due dette varietà, parmi si possa
pensare ancora ad un meccanismo diverso, e mi dimando: é possibile che in questi casi
si tratti di parietali sorti, come nel caso di Fusari, da tre germi d'ossificazione? Am-
mettendo una precoce sinostosi fra il germe anteriore ed il posterior-inferiore si com-
prenderebbe la divisione del parietale per separazione dell' angolo occipitale; ammet-
tendo la sinostosi fra il germe anteriore ed il posterior-superiore, si comprenderebbe la
divisione del parietale par separazione dell' angolo suo mastoideo; ammettendo la
sinostosi del germe posterior-superiore coll' anteriore e col posterior-inferiore si com-
prenderebbe la divisione del parietale per separazione incompleta dell'angolo suo mas-
toideo, imediante una breve sutura soprannumeraria verticale come nei casi di Gruber
e m1O.
This latter hypothesis has the advantage over the former, “che l'origine del pari-
etale da tre germi è un fatto (si pure una sola volta) constatato e che essa ha il vantaggio
di darci ragione della forma e della grandezza del pezzo del parietale separato, dell'
audamento della sutura anomala, e ci permette di spiegare facilmente tutte i singoli
casi compressi nelle due dette varietà.”
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 329
of the 10wer part of the parietal which are separated by these
extremely rare fissures can be referred to the Wormian bones
(Schaltknochen).”
Ranke's opinion as to the sutures that separate only an
angle of the parietal differ from all the preceding (36, pp. 33–
35) is, that the separations of the mastoid angle “possess
something decidedly typical.” Nevertheless I should not fully
agree with Putnam's supposition that in these conditions we
have to deal with a primarily “separate center.” “Yet, the
oblique and the Sagittal parietal suture, cutting into the
parietal from the same point (posteriorly), have something in
common in development.”
Ranke considers Putnam's case as similar to his three
cases of an incomplete Sagittal Suture, and on this assumption
(incorrect in view of the more detailed description of the
case here given) bases the following conclusion: “When
we accept that the (posterior) incomplete horizontal resp.
Sagittal parietal suture and the oblique parietal suture are
primarily the same formations, it still remains for us to ex-
plain why under these circumstances the incomplete sagittal
parietal Suture suffers a deflection downward, so that it changes
either wholly or in its anterior part from a sagittal to one of
an oblique direction.”
Ranke's above statement embraces the theory of an identity
Of the posterior incomplete horizontal parietal suture with (at
least) that which passes in an oblique or angular direction,
between the posterior and the inferior borders of the parietal,
Separating its mastoid angle, or, rather, its postero-inferior
portion; and the existence of conditions capable of deflecting
the horizontal suture downward and making it reach the
inferior parietal border. The deflection of the suture is pro-
duced, according to Ranke, “through a break (Einknickung)
in the ‘plastically' (after G. H. Mayer) upturned posterior
border of the parietal.” He says: “It is my opinion that
these formations occur mostly in a similar way as the
* “Sind. Schon aus früheren Entwickelungsepochen kürzere. Sagittal Spaltungen im
jºin vorhanden, so führt die Abknickung diese Spalten in der Knickhaute nach
abwärts. :
330 Bulletin American Museum of Natural History. [Vol. XIX,
artificially produced sutures by Gudden, and that is by the
cracking (Einknickung) of the skull in consequence of the
counterpressure (maintained by Mayer º) of the spinal column
against the heavy, exceedingly pliant and breakable skull.
In instances where there are no primary Sagittal clefts in
the parietal, which would facilitate the cracking in a definite
direction, there will be split off, through the same process and
parallel with the lambdoid suture, quadrilateral pieces of the
parietal, those well-known so-called ‘colossal intercalated
lones (Schaltknochen),” which are in reality pieces of the
parietal bone, and are mostly separated from the neighboring
parts by well-formed and serrated sutures.”
On pages 63 and 64 of his memoir, Ranke reiterates his
opinion, and his final expressions on the point are as follows:
“The investigations into the development of the parietal
Done have brought forth no better explanation of the oblique
parietal suture than those previously attempted. In any case,
there is no ground on which we could attribute to the sepa-
rated, independently appearing mastoid angle the same sig-
nificance with the inferior elementary parietal, as was the
desire of Gruber. Neither can I agree unconditionally with
the ideas of Toldt, who also means that, without anything
further, he can refer the condition, equally as the separation
of an “upper ' from a “10wer half,’ to the “typical dicentric
foundation' of the parietal.” “I would adhere primarily to
the before expressed opinion, that in cases of the “oblique
parietal suture we have to deal with a deflection, due to
some, perhaps a mechanical, cause, of that, even in the new-
lborn, so frequent, posterior incomplete Sagittal parietal suture;
this suture through a mechanical breaking off of the mastoid
angle not only is bent downward, but carried even to the
border of the parietal.” “It should, however, also not be
passed over in silence that such a small separation, as shown
on fig. I3, p. 303, can arouse the thought that here, perhaps,
we are confronted with something that is no more than a
fontanel-bone.”
. Gudden, Experimentaluntersuchungen ü. d. Schädelwachsthum, München, 1874.
2 Mºyer. G. H., Statik und Mechanic d. menschl. Knochengerüstes, Leipzig, 1873, pp.
233-230.
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 33 I
No opinion has thus far been formulated (unless it was by
Zoja, whose publication was not accessible to me) in regard
to the instances of an apparent extension of a parietal divi-
sion into the temporal Squama.
Résumé: Causation of Parietal Divisions in Man.
The above notes illustrate that we are confronted by a
number of more or 1ess varying theories, formulated mainly
on the basis of the rather scanty human material, both as to
the fundamental and the determining causes of parietal divi-
sions, particularly those of a very oblique course or extending
between two connecting, instead of two opposed, borders of
the parietal. -
In so far as the fundamental cause of the “typical” sagit-
tal divisions, are concerned, there is a general agreement as
to the development of these by an independent growth of,
and the eventual forming of, a regular articulation by two
portions of the parietal, the only points of difference among
the authors relating to the exact morphological value of these
two portions. As to the very oblique and the infero-pos-
terior divisions we have several radically distinct tendencies
of opinion. There is a series of authors who are inclined
to consider these divisions as equivalent with the “typical”
sagittal ones, or, at least, developed as a consequence of , a
separate center of Ossification of the parietal; a Smaller group,
represented mainly by Coraini, who associate the additional
portion of the parietal with intercalated bones; and finally
one observer, Ranke, looks upon these formations as at me-
chanically extended normal foetal fissures which are ordi-
narily found in the posterior border of the parietal bone.
As to the determining cause of the anomaly in its “typical”
form, we have the theory of Calori and Coraini, which attrib-
utes the formation of the additional parietal bone and the
subsequent parietal suture to the effects of a disproportion
from physiological or pathological cause between the growth
of the cranial contents and the cranial vault; and the theory
of Virchow and particularly Ranke, which seeks the cause
332 Bulletin American Museum of AWatural History. [Vol. XIX,
in a premature union of other normal cranial sutures, and the
consequent increased strain on the separation between the
two embryonal portions of the parietal, if this separation hap-
pens to be still open; and, somewhat indirectly, the implied
theory of reversion or reminiscence, of Maggi. The determin-
fing cause of the very oblique antero-posterior, the infero-pos-
terior and other parietal divisions is, with those who consider
these divisions as equivalent to the “typical” ones (includ-
ing, notwithstanding their varying view of the whole subject,
Calori and Coraini, as well as Maggi and Frassetto), evidently
primarily the same as that of the “typical forms.” For
Ranke, as we have seen, the cause of these atypical parie-
tal divisions is entirely different from that of the “typical”
ones, and consists primarily in the counterpressure of the
spinal column against the cranium, the influence inducing
direct or indirect breaks in the postero-inferior part of the
parietal bone, which breaks persist in the form of a suture.
The Morphological Value of the Complete Antero-Posterior
Parietal Divisions in Man.
The differences of opinion as to the morphological value
of the two portions of the Sagitally divided parietal are repre-
sented by the views of Toldt, Maggi, Calori, and Ranke. Toldt
held that two separate portions develop from the ordinary
two foci of Ossification, to which foci he attributed no special
significance; and Maggi’s (with Frassetto's) position, though
assuming more than two centers of Ossification for the parietal,
is similar. For Calori, and particularly Coraini, of the two
portions of a divided parietal, one represents the real, origi-
na1, the other an accessory, Wormian-like bone. For Ranke
the two portions represent two ab origine distinct and equiva-
lent parietal bones.
Of these several views that of Calori and Coraini appears to
me to be the least tenable. It is true that large “accessory”
bones occur in the 1ocation of the foetal fontanels and in
all the normal parietal sutures. It is also true that in ex-
tremely rare cases the accessory bone, particularly that which
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 333
occurs in the temporo-parietal suture, may extend, with one
or more interruptions (and possibly continuously), along the
whole border of the parietal; I have seen two or three in-
stances of that condition and find several such cases on
record. But the “typical” sagittal parietal divisions have
characters of their own which will easily differentiate them
from the formations just referred to. Let us take such a case
as Soemmering's, or Ranke's, or those of Turner. Both por-
tions of the divided parietal in these cases are large, though
the upper exceeds more or less the 10wer one; the parieto-
temporal accessory bones have never been seen to attain at
any point comparable dimension. The suture that separ-
ates the two portions of the divided parietal is usually well
serrated, though it may at the same time be slightly to mod-
erately squamous; the suture that separates the accessory
temporo-parietal bone from the parieta1 is only and eminently
Squamous. The accessory formations are, with the rarest ex-
ceptions, very irregularly subdivided, but there is no instance
where either portion of a sagittally divided parietal has shown
the slightest indication of a subdivision. Calori and Coraini
suggest that the large accessory bone may have been pro-
duced from but one accessory center, which brings their theory
very much nearer that of Toldt and his followers; but how
can we account, especially in the absence of marked signs of an
excess of a physiological brain-growth, a hydrocephalus, or
other abnormalities, for a development of the necessarily
Secondary and later “accessory” center, equalling, or almost
equalling, the original center of ossification of the parietal?
It seems to me that on the basis of these considerations alone,
and without reference to the embryological data now in our
possession, or to the normal partial parietal divisions in the
new-born in a situation corresponding to that of the anoma-
lous, complete, “typical” division, the accessory-center theory
of the origin of the “typical” sagittal parietal divisions must
be abandoned.
Toldt's, Maggi’s, and Ranke's views differ essentially in the
attributed morphological value to the two centers from which
the “typically ” divided, as well as the ordinary, parietal
334 Bulletin American Museum of AWatural History. [Vol. XIX,
develops. For Toldt and Maggi the centers have apparently
no different meaning from that of similar centers of other
cranial and skeletal bones; for Ranke, it does not appear
on what basis, they represent two distinct parietals. Should
Ranke's view be correct, and as we do not meet with double
parietals as a regular feature in lower mammal life, we should
be in the presence of either an early stage of a highly inter-
esting neomorphism or appearance of a new cranial bone, or a
very far-reaching reversion, such as implied by Maggi. The
presence of a double parietal would then either denote a sign
of Organic precociousness, and individually rather a progres-
sive character, a superiority; or a very inferior animal feature.
There would be little need, then, of searching for a cause of
the “typically” divided parietal in the pathological prema-
ture Synostosis of Some of the normal cranial sutures. Also,
there is no barrier which would restrict the idea of an equiva-
lence of the centers of Ossification with distinct bones, to the
centers of the parietal; it would have to be extended to the
centers of other bones, the occipital, the malar, the superior
maxilla, the Scapula, pelvic bones, femur, etc., which would
give an entirely different aspect from that which we now have
of our osteology, and for this we are as yet hardly prepared.
However, Ranke's theory cannot be lightly disposed of. It
seems to disturb our current notions about bones; but it only
seems so, for upon reflection it must be acknowledged that
we have no clear and generally established notions relating
to the morphological value of the centers from which our
bones develop. What proofs, or even indications, are there
that our adult bones are primary morphological units and not
composites of different, at some period in the individual or
even terrestrial life, independent parts? There are not only no
such proofs, but there is much that favors the assumption that
our adult bones are such composites, that they are really phylo-
genetic and ontogenetic resultants from a varying number of
more or 1ess independent bone units. We do not consider a
normally synostosed cranium or a part of the spinal column
or any other portion of the skeleton a single bone, yet the
relation between an adult bone and its early constituents, and
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 335
the synostosed cranium and its early constituents, is more an
apparent than a real one. It is decidedly attractive and seems
possible to look at the early steady constituents of all the adult
skeletal parts as at separate formations, separate units of the
organism. They do not, however, it seems to me, represent
distinct “parietals,” or “malars,” or “maxillae,” or “scapulae,”
etc.; these terms belong only to the composites, to the SynOS-
tosed aggregates, of the earlier, elementary portions. In the
case of the “typical” division of the parietal it is not two
parietals that we have, so much as two parts of the parietal, or,
at most, two persisting elementary parietals. Properly, we
should not speak of these cases as divisions, but rather as
of anostoses of the parietal; and, similarly, of anostoses in-
stead of divisions of the malar, etc.
The Morphological Value of the Very Oblique Divisions and
those that Run between two Connecting Borders of
the Parietal in Man.
Due to their location and extent, the very oblique antero-
posterior and the injero-posterior parietal sutures have been
separated into a special group, and are considered, princi-
pally by Ranke, as being of a different signification from the
“typical” Sagittal sutures of the parietal bone. Such a sepa-
ration is, so far as the very oblique antero-posterior sutures
are concerned, entirely artificial. There is no such a thing
as a “typical” sagittal suture. In all the instances of a bi-
partite parietal the suture was more or less oblique, never
perfectly horizontal, that is, terminating at exactly the same
distances from the pterion and asterion as from the bregma
and lambda; and there were observed, without any great in-
terruption, all the degrees of obliquity. There are cases
on record, speaking still exclusively of man, where the suture
nearly halves the parietal antero-posteriorly, as in Soemmer-
ing's specimen and others, particularly two of the foetal skulls
of Hyrtl, where the division runs very nearly from one angle
of the parietal to an opposite angle. In such circumstances
on what basis can we separate morphologically any special
336 Bulletin American Museum of Natural History. [Vol. XIX,
number of the antero-posterior sutures from the others?
Toldt's and Ranke's embryological investigations both show
that the elementary parts of the parietal are seldom, if ever,
situated perfectly one above the other; and if not so at that
early stage of life, why should we wonder at finding them in a
similar, perhaps more or 1ess accentuated, position later? The
accentuation of the obliquity of the space, later on, suture,
between the two parts, is easily explainable by differences in
growth of the two, differences which we know to exist, for
probably the parts are never, when full grown, of the same
dimensions. There seems to me to be no possibility, unless
Some further evidence of their difference is adduced, of sep-
arating the more from the less oblique antero-posterior sutures
of the parietal, and I cannot but second the opinion of Toldt
and others, that the more oblique antero-posterior parietal
Sutures are morphologically identical with the less oblique ones
that cross the bone in the same direction. They both form
the boundaries between the variously developed, persisting
elementary parts of the parietal.
There is a greater difficulty in determining the proper sig-
nificance of those portions of bone which occasionally repre-
Sent in a separate state more or 1ess of the postero-inferior
portion of the parietal. The sutures separating these differ
in nothing, except in a greater tendency to angularity, from
the antero-posterior parietal sutures. In 10cation they range
from those that run from the middle of the posterior to, or
even anterior to, the middle of the inferior border of the parie-
tal, to those that are unmistakably the boundaries of Wormian
or fontanel bones. Their posterior termination, as Ranke re-
marks, is mostly at about the same point as that of the antero-
posterior sutures. The bones which these postero-inferior
Sutures represent have distinctly the appearance of parts of
the parietal. They never encroach in any marked degree, as
Wormian or fontanel bones are apt to do, on the neighboring
bones, nor have they been seen to be in any way subdivided,
or to extend into the temporo-occipital suture, or appear ex-
tended by Wormians along and at the expense of the pos-
terior or inferior parietal border.
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 337
There are, as mentioned, in the main, three theories about
these “separations” of the postero-inferior portions of the
parietal. Of these the theory of Ranke, attributing them to a
mechanical separation extending in the course of the partial
posterior parietal suture, appears to be the least tenable. In
the majority of instances of the anomaly there is no evidence of
any turning up of the posterior border of the parietal, nor any
other abnormality which would point to any special effects of
the counterpressure of the spinal column. The first effect of
such a counterpressure in a case of an abnormally yielding
skull is exerted on the base of the skull, and results in a de-
pression of the region about the foramen magnum. Should
the effects of the counterpressure of the spinal column lead to
a cracking of the parietal, it is reasonable to suppose that a
similar effect would be even more observable on the more
directly affected occipital bone, which is also provided at
birth, and considerably after birth, with incomplete sutures;
but thus far there is no evidence of any such cracking on the
occipital. I have examined more than a dozen skulls with
a more or less pronounced basal depression, and quite a large
number of crania with various, in some instances very pro-
nounced, degrees of turning up or bulging of the posterior, or
anterior, or both posterior and anterior parietal borders, with-
out finding any cracks or a separation of mastoid or other
angle. Besides this, it is well known that in cracks or frac-
tures of the parietal there is generally a tendency, even in
adults, to repair and not to a persistence of the separation;
and, if it occurs in addition, why should the cracking in the
posterior part of the parietal lead always downward, and
never very irregularly, as is common with fractures, or for-
ward or upward?
There is another consideration to which I have referred in
a previous publication (37, p. 289 et seq.), namely, how can a
turning up or bulging of the posterior border of the parietal
affect, without apparently displacing its posterior termination,
the anterior end of the incomplete parietal suture? This
suture, which is dealt with more in detail in another chapter,
is the remnant of the space that exists normally in foetal life
[?une, 1903.] 3%
338 Aulletin American Museum of Matural History. [Vol. XIX,
between the distal portions of the growing and centrally
united segments of the parietal. This being its origin, its
course must always lie in the line of the union of the seg-
ments, and this line points generally towards the parietal
eminence. By the time the posterior parietal border comes
in contact with the occipital, the posterior incomplete parietal
suture is bounded both superiorly and inferiorly by firm bone
substance, under which circumstance it is quite impossible to
imagine any disturbance, mechanical or pathological, that
could affect mainly or solely the more central portion of the
suture, and deflect as well as extend it downward to the in-
ferior border of the parietal. There are, to quote partly from
my previous paper on this subject, only two factors that could
possibly affect and modify the course of the incomplete pos-
terior parietal suture, and both of these would show their in-
fluence mainly or entirely on the distal portion of the same.
These two factors are, first, an abnormal development, either
defective or excessive, of the posterior part of one of the origi-
nal parietal segments; and, secondly, influences that would
interfere with the freedom of full growth of the posterior
border of the parietal. In the instances of the first order, as
can easily be imagined or even artificially demonstrated, there
would be possibly only a lower or higher situation or an ob-
liquity affecting mostly the marginal portion of the division.
The results would be oblique or curved sutures diverging from
the parietal eminence,— effects entirely different from the
actually observed oblique sutures that sever the lower portion
of the parietal, or its mastoid angle.
Influences interfering with the free development of the
posterior border of the parietal bone could only deflect up-
ward or downward the marginal end of an incomplete parie-
tal suture; only in cases of a very short suture could they
possibly render it oblique or curved in its entirety. But even
in these cases it would be the peripheral termination of the
suture that would be mainly affected. Of this, however, the
known instances of postero-inferior parietal sutures, in man
or other mammals, afford no illustration.
A theory which meets with so many practical difficulties
1963.] Hrdlička, Parietal Bone in Man and Other Mammals. 339
as the theory of Ranke under consideration, should not be
accepted before it can be supported by more convincing argu-
ments and practical demonstrations.
The above considerations do not, of course, deny the possi-
bility of an ordinary parietal fracture from the usual causes
of such an accident, and the possibility of this fracture appear-
ing similar to, or even indistinguishable from, a postero-inferior
parietal suture. Actually I was not able to find any record
or any example of such a fracture; but that does not make
it an impossibility. I have seen several skulls where the
ordinary, more or 1ess irregularly Sagitta1 or vertical parietal
fracture simulated very closely an anomalous parieta1 su-
ture. Gruber (22) describes one case as an instance of an
oblique parietal suture, while Hyrtl and Ranke both con-
sider that case as one with an acquired division. To differen-
tiate a congenital real oblique suture from a division which
is the result of a fracture, we must be guided largely by the
situation, form, and serration of the division, and the con-
dition of the surrounding bones, especially that of the opposite
parietal. A straight course, ending with one extremity in or
near the middle of the anterior or posterior border of the parie-
tal, a complex Serration, no continuity of the division on the
neighboring bones or multiplicity, and particularly a co-exist-
ence of an allied or similar division on the opposite parieta1,–
all favor the conclusion that the division under consideration
is a real congenital suture, and not the result of a fracture.
As to the theory of a morphological equivalence or identity
of the minor portions of the parietal separated by an infero-
posterior with the inferior ones separated by an antero-
posterior suture, there are reasons to believe that in at least
some instances this view is a correct one. Without adducing
in this place the evidence of other material than that in man,
we have one fact of considerable value in support of this
opinion. This fact is the almost general and sometimes (cases
of Gruber, Putnam) véry marked preponderance anteriorly of
the Superior over the inferior part of the bipartite parietal.
In view of this fact it beomes very probable that at times the
relative position and growth of the elementary parietals may
34O Bulletin American Museum of Matural History. [Vol. XIX,
lbe such as to condition an inferior instead of an anterior ter-
mination of the parietal suture. We shall return to this
point later, when considering the evidence afforded by the
material on monkeys.
The accessory- or Wormian-bone theory of Calori and Cor-
aini, to which also Graf Spee inclines, would be more defensible
if we still held to the old view of the one-center develop-
ment of the parietal. Yet, even with our present knowledge,
the compensatory-bone theory cannot be entirely refuted,
and may be right in some instances. The formation of
accessory bones arising from accessory foci of Ossification in
places of defects of the normal bones is the rule, and occasion-
ally such bones reach dimensions which fully equal those that
appear to be the separated postero-inferior part of the pari-
etal. The mastoid angle of the parietal develops somewhat
1ater than the other angles of the bone, which rather favors
the development of accessory bones in the posterior lateral
fontanelles. Due to these facts, in some instances, such as one
of Ranke's cases (36, fig. 13) or the Peruvian in my former
paper (37, fig. 6), a diagnosis between a part of a parietal,
developed from an original center, and a Wormian or fontanel
bone, developed from an accessory and relatively late focus of
Ossification, is, I believe, impossible. But we can not ex-
tend the accessory-bone explanation to all the independent
pieces of bone that form postero-inferiorly a portion of the
parietal. I have adduced some of the reasons for this before,
lout they may be repeated. In the first place, as even Ranke
acknowledged, the majority of the postero-inferior sutures
have something characteristic, in that they terminate pos-
teriorly in nearly the same location, which corresponds to the
1ocation of the normal incomplete posterior parietal suture, or
the remnant of the original space between the two elementary
parts of the parietal. In the second place, there were not
observed in the recorded cases of the postero-inferior parietal
suture signs of an inordinate cranial distention or other
marked defects in the Ossification of the normal cranial bones,
which, though perhaps not constant, are certainly more fre-
quent in crania with the more marked Wormian formations.
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 34I
The real postero-inferior fontanel bones are usually irregu-
lar in form; all intercalated bones tend to encroach on all the
Surrounding parts; and there is a pronounced tendency to
multiplicity in the intercalated bones — all of which is differ-
ent with the portions separated by the postero-inferior parietal
Suture.
As to the suggestion of Coraini that in these cases the acces-
sory bone Ossifies from One accessory centre and represents an
advanced phase of a Wormian formation, it may be remarked
that the single Wormian bones are passive results of conditions
in individuals, and can have no definite history of their own,
no regularity, no phases of evolution. Should ever a Wormian
bone show a tendency to a regularity and differentiation it
would be on the road to become a new cranial member, equiv-
alent with the normal cranial bones, and cease to be a Wormian.
Coraini’s reference to the possibility of an occasional devel-
opment of the parietal from three centers is, leaving the
“accessory” denomination of two of the centers aside, well
worth consideration. There is but one, and that not very
Satisfactory, case in man (Fusari's) of a tripartite parieta1;
but there are several cases on record of a distinctly angular
postero-inferior parietal suture which could be most satisfac-
torily explained on the basis of a tricentric, not, however,
necessarily Maggi’s, theory. This point, also, will be more
advantageously treated later.
The Determining Causes of Parietal Divisions in Man.
The subject of the determining causes of the bipartite
parietals has been partly touched upon. The objections were
stated in regard to Ranke's theory of breaks, due to the coun-
terpressure of the spinal column upon the cranium, as causes
of the very oblique antero-posterior and the infero-posterior
parietal sutures. Calori's and Coraini's theory of a dispropor-
tion of growth between the cranial bones and the cranial con-
tents, with the consequent detraction of nutrition from the
Original One, and an appearance of an accessory center, must
fall, as it is mainly with the old one-center view of the
342 Bulletin American Museum of Natural History. [Vol. XIX,
development of the parietal. The theory can, however, be
slightly modified and made to apply to the di-centric or tri-
centric parietal. The question arises, could such a dispropor-
tion of growth between the cranial contents and vault, due
either to physiological or pathological causes, prevent the union
of the elementary parts of the parietal? Such disproportions of
growth, particularly those due to pathological causes, above all
hydrocephalus, do occur; but do they ever occur early enough
to prevent the normal very early union of the parietal portions?
This question can be properly answered only by further re-
search in embryology. Should in any instance the normal
union of the parietal portions be delayed until those periods
in the foetal life in which we know hydrocephalus to occur, it
is very probable that the condition would further delay, from
the very causes mentioned by Calori (mechanical and effect
on nutrition of the bones), the union of the parts, or even
induce their persistent separation. That a hydrocephalus or
any other condition could ever separate centers that have
already more or less coalesced seems highly improbable.
Virchow's and Ranke's theory attributes the determining
cause of the “typical” sagittal parietal sutures to a prema-
ture union of some of the normal cranial sutures. This hypothe-
sis evidently comprises two distinct elements, acting more
or less conjointly or even interdependently, namely, a retarda-
tion in the normal closure of foetal divisions of bones and a
very premature synostosis of sutures which normally persist
well into life. Applied to the parietal bone it presumes, to
start with, besides the existence of a complete separation of
the two foci of Ossification, also a separation of the two por-
tions of the parietal bone developing from those foci up to
the time of the formation of the parietal articulations. When
the parietal centers fuse normally, the event occurs much
earlier than the meeting of the parietal with other bones and
the formation of cranial articulations, hence much earlier than
|before synostosis is possible. If a union of the elementary
parts of the parietal is present from another cause until the
occurrence of a premature synostosis of some cranial articula-
tion, this latter event will undoubtedly favor the persistence
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 343
of the parietal suture. The cause is of approximately equal
value with that of hydrocephalus. It does not reach the
primary cause of the parietal suture: the retardation of the
parietal union.
Both Coraini and Ranke suggest, though the latter only
indirectly, that the bipartite parietal represents a neomor-
phism. Should this view be correct, the retardation of the
union of the elementary parts of the parietal would be attribu-
table to the trophic nervous centers, under whose direction
or influence all growth proceeds. The objection against neo-
morphism is the extreme rarity of the anomaly in man. The
phenomenon might be imagined as neomorphism in a stage
of otherwise overcome need or a stage of failure, and then
really a sort of atavism, - but with the material on man alone
this would be mere conjecture.
Maggi’s view of the homology of the divided parietal with
certain conditions in the Stegocephali, Batrachians, etc., needs,
to say the least, very much further study and demonstration.
Critical Remarks Concerning Parietal Divisions in Apes,
Monkeys, and other Mammals.
After the above considerations, which were made solely in
reference to man and on the basis of previously known mate-
rial, it remains for us to briefly point out in which way the
material on apes, monkeys, and lower animals, including that
here published, influences the discussed theories concerning
the various parietal sutures.
Perhaps the most striking phenomenon of those that may
now be considered as fairly established, is the absence or
excessive rarity of all forms of parietal separations in the
lower mammals, up to the monkeys; the sudden frequency of
such divisions in monkeys, particularly in certain groups;
and a probably, similar frequency in the apes, or at least in
the orang and chimpanzee. The frequency of the anomaly
in man is considerably less than that in monkeys and apes,
though greater than that in the carnivora and lower mammals.
There are no traces of any pathological conditions, such
344 Bulletin American Museum of Matural History. [Vol. XIX,
as hydrocephalus; no traces of premature Synostoses of nor-
mal sutures; and no traces of any effects of a counterpressure
of the spinal column upon the skull. This shows plainly that,
at least in the apes and monkeys, parietal separations are not
due to any of these conditions. Parietal separations in apes
and monkeys seem to be examples of disturbed normal de-
velopment, or dismorphism, with, perhaps, a tendency towards
neomorphism. The much more frequent occurrence of the
separations in monkeys and apes than in man makes it possible
that, after all, the anomalies in man may represent more or
less a sort of atavism.
Parietal sutures in the apes and monkeys show a greater
variety in location than those in man. Among this variety
there is a very marked preponderance of vertical, and a rela-
tive scarcity of Sagittal, Sutures in the monkeys; in the apes,
and particularly in man, it is the Sagittal sutures that pre-
ponderate. This phenomenon can only be explained by an
assumption of a difference in the relative location in monkeys
and apes with man of the centers of ossification of the parie-
tal. In monkeys these centers are apparently mostly an-
terior and posterior, in the apes and man almost as a rule
more or less inferior and superior, or, rather, ranging from an
antero-superior and postero-inferior to almost perfectly supe-
rior and inferior. There has been manifested somewhere
between monkeys and apes a tendency towards a reaccommo-
dation of the not very steady position of the centers, directed,
in all probability, towards an arrangement more suitable to
the needs of the higher organism. With the various cases in
monkeys and apes at hand, it is easy to understand the oblique
parietal sutures and even the more or less vertical ones, as
those of Fusari and Coraini. The vertical parietal sutures in
man represent apparently a greater degree of atavism than
others.
In several of the monkeys and particularly in the chimpan-
zee, we have a practical demonstration of the mode of forma-
tion of those parietal sutures that run between two continuous
borders. In the chimpanzee the suture is equivalent to the
antero-posterior one of the other parietal; in this case both
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 345
the parietals developed from two elementary parts. In some
of the monkeys (cases 47 and 48), on the other hand, it is
clear that the parietal developed from three centers. Case
47 is particularly instructive, showing the formation, by an
early synostosis between the anterior and the postero-superior
parts, of the “separation of the mastoid angle.” Barring the
“accessory” nature of any of the parts, this case is a beautiful
illustration of Coraini’s hypothesis relating to the angular
postero-inferior parietal sutures and a proof of the validity in
at least Some cases of Maggi’s three-center theory.
The theory of an identity of the minor parietal separa-
tions with Wormian bones finds no support and much contra-
diction when our observations are extended to apes and
monkeys, in which formation of even very small intercalated
bones is quite a rarity.
A number of very interesting observations which require a
Special notice is presented by the parietal separations with
an apparent extension into the temporal or frontal squama.
Only two such cases have been thus far mentioned in litera-
ture. One of these, of which I have no particulars, not having
been able to obtain the publication, was described by Zoja
(52), while the other has been mentioned in the following
words by Graf Spee (51, p. 115): “There is in the local (Kiel)
anatomical collection a skull in which the temporal squama
is divided into an upper and a lower half by a sagittal suture.
This division proceeds backward into the parietal bone, in
the direction of the summit of the occipital bone, without,
however, reaching the lambdoid suture. The pieces of the
upper part of the temporal squama and lower part of the
parietal bone, separated by this extremely rare suture, are
perhaps referable to intercalated bones (Schaltknochen).”
Graf Spee’s explanation of the anomaly is not applicable
to the cases that came under my observation, where the ap-
parent prolongation of the parietal suture or fissure was mostly
incomplete, and often directed in such a way that there was
no possibility of its having been a part of the boundary of any
intercalated bone. In these cases we have to search for
another explanation.
346 Bulletin American Museum of Natural History. [Vol. XIX,
It is not impossible that in extremely rare cases two inde-
pendent sutures or fissures, each in a different bone, may ter-
minate opposite each other in such a manner as to appear
like one division; or that both divisions are the unrecog-
nized results of fracture. However, the more ordinary and
perhaps almost regular origin of these separations which
seem to continue in the adjacent bone, is, I believe, as
follows: -
It is a well-known law (Virchow) that all persisting sutures
or fissures in a bpne, such as the parietal, favor a greater
growth of so much of the bone as is affected by the separa-
tion, than takes place in the parts not so affected, and the
augmentation takes place principally at right angles to the
separation. Granted that we have a more or less vertical
division of some sort in the inferior portion of the parietal,
this portion will increase in length. If in a rare instance this
increase shall be hindered by a firm articulation with the tem-
poral squama, there will be developed a state of tension acting
on the squama, and under such conditions a jar or a blow, or
possibly even the strength of the tension itself, may cause a
fissuring, of the squama. --Other bones than the temporal are
not so often affected by such a fissuring because of their
greater strength and resistance.
This theory is able to account for all the instances of a
parietal suture or fissure with an extension that I have come
across, and may account for others. Why the anomaly is not
present in all cases in which a parietal division terminates in
the inferior border of the bone, can only be explained by the
suppositions that in such cases either the border of the Squama
is very resistant, or it is not firmly articulated with that of
the parietal, or, finally, it grows at a like rate with the parie-
tal border. - - -
A notable fact about the anomalous parietal sutures is their
preponderance in the male sex in man, while no such differ-
ence is marked in monkeys. The phenomenon is not easy to
explain or even to form a plausible theory in relation to. It
nevertheless seems to indicate that some one or more of the
characters by which, regularly or perhaps but occasionally, the
1903.] Hrdlička, Parietat Bone in Man and Other Mammals. 347
male skull differs from the female, act in their earliest or foetal
stages as direct or indirect causes of the parietal division.
The occurrence of the anomaly in the female would then be
explainable by the presence in the particular skull of those
same masculine characters to which the just-made reference
may be applicable. What these characters may be is thus
far purely a matter of speculation. They could, perhaps, be
detected if all the known specimens of complete parietal
sutures could be brought together and be carefully re-exam-
ined and measured, and compared with average normal male
and female crania of the same nationalities to which belonged
the skulls with the anomaly. s
A few words in conclusion about the relation of the parietal
sutures with the temporal ridges. The relation between the
complete Sagittal sutures and the Superior line of the ridge,
which Hyrtl hinted at, is now well known to be but acci-
dental (v. Ranke), and it is clear that neither part of the
ridge can stand in any etiological or morphological relation
with the vertical or very oblique parietal sutures. It is true
that the anterior extremity of the complete or incomplete
Sagittal parietal suture in man terminates not infrequently
near or in that portion of the ridge that crosses the coronal
suture, but this seems to be mainly, if not entirely, due to the
fact that normally and independently both the ridge and
suture reach the anterior border of the parietal near the
same point.
General Conclusions.
All the data thus far adduced make possible the following
main conclusions:
(1) Complete separations in the parietal bone are nearly, if
not entirely, restricted to monkeys, apes, and man.
(2) The separations are much less frequent in man than in
apes and monkeys. They also are not equally frequent in
all the subdivisions of apes and monkeys, and possibly in the
different races of man, but in the latter this point is still
uncertain. In man there is a preponderance of parietal
348. Bulletin American Museum of Matural History. [Vol. XIX,
sutures in the males, but in the monkeys the Sex Seems to
have but little influence on the frequency of the anomalies.
(3) The parietal sutures are divisible into two main groups,
namely, into those that run between two opposed, and those
that run between two connected, borders of the parietal. The
former group comprises all the complete antero-posterior and
infero-superior, the latter group, all the other oblique or
angular Sutures.
(4) There is a marked preponderance of infero-superior
and scarcity of antero-posterior sutures in monkeys, while the
reverse is the case in apes and man. Of the minor complete
divisions the ones almost exclusively met with in man are the
postero-inferior ones; in monkeys and apes we meet with
these and also with postero-Superior, antero-superior, and
antero-inferior sutures.
(5) The possibility of the major parietal separations is
explainable by a persistence of the original separation between
two regular and ordinarily early coalescing centers or elemen-
tary parts, with which we became acquainted mainly through
the researches of Toldt and Ranke. The presence of a congeni-
tal major division of the parietal of an ape, monkey, or other
Imammal is only explainable on a similar basis. Judging from
certain cases, particularly in monkeys, the development of the
parietal may take place from more than two centers; how
frequently this is the case remains to be determined by further
embryological investigations.
(6) The difference in 10cation of the major parietal su-
tures in man with apes and monkeys points to a different
Original location of the parietal centers. There is also prob-
able, in view of the variety of parietal separations, a lesser
fixity of the centers, both in location and number, in the
nonkeys than in man.
(7) A preponderance of growth in one of the elementary
parts is accountable for the smaller differences in the location
and direction of the major sutures, and the same condition,
if excessive, may produce a suture that runs between two
continuous borders of the parietal.
(8) The majority of the parts of bone that are separated
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 349
from the body of the parietal by a suture, particularly an
angular suture, that runs between continuous borders, are
developed from one of the original parietal centers.
(9) The occasional smaller bones that bear the aspect of
parietal separation cannot be distinguished from the purely
compensatory (Wormian or fontanel) bones, developed from
accessory foci of ossification.
(Io) The determining causes of the various parietal separa-
tions are divisible into primary and contributive. The pri-
mary cause of the anomalies in the monkeys is probably
dismorphism, a disturbance of development originating in the
trophic centers, perhaps more or less allied to neomorphism;
in man the cause is probably what may be termed a reminis-
cence, or a mild form of atavism. A reversion reaching much
farther back in the organic life can not be accepted without
much satisfactory demonstration. The contributive causes
of the parietal divisions, which can become effective only after
the influence of the primary ones has been manifested to a
certain degree, are all those conditions which more consider-
ably augment the intracranial pressure, such as, in man, hy-
drocephalus and very premature closure of some of the normal
cranial sutures.
(II) The apparent extensions of parietal sutures, complete
or incomplete, are almost restricted to the temporal Squama,
and are, at least in the majority of instances, acquired pro-
ducts, due principally to the tension produced by the aug-
mented growth of the portion of the parietal affected by the
Separation.
(I2) Neither part of the temporal ridge stands in any causa-
tive or morphological relation with any kind of parietal
sutures; but the ridges affect the synostosis and more or less
the course of the sutures, if these extend into or across the
ridges or into their close neighborhood.
A number of points not touched upon here will be explained
in the following chapters.
350 Bulletin American Museum of AWatural History. [Vol. XIX,
VIII A. PARTIAL DIVISIONs of THE PARIETAL DUE TO THE
MANNER of OSSIFICATION OF THE Bone,
The conditions which will be discussed under this head can-
not be considered as abnormal, unless they persist beyond the
age at which they regularly disappear.
The parietal bone in man, monkeys, and probably also in
Other mammals, develops usually, as was shown in another
division of this paper, from two, and occasionally from more
than two, centers of ossification, or elementary parts. These
parts grow rapidly in all directions until their convex borders
meet at some point, soon after which in normal cases they
begin to fuse at this point of contact. As the two parts grow,
which they apparently still do quite independently, though
in the process of fusing, their median borders gradually extend
their apposition and synostosis in the direction from the Original
point of contact, which usually corresponds to the eminence
of the parietal, towards the periphery. Between the portions
in contact and the periphery there is always in man in the
foetal life, and occasionally beyond this, anteriorly and espe-
cially posteriorly (where the growth of the parts seems to be
slower) a more or less wide wedge-shaped membranous space;
Or, in 1ater stages, a fissure or suture-like separation. In the
full term foetus the anterior separation has in most cases
already disappeared; the posterior cleft, fissure, or suture,
which still mostly persists, is situated generally not far from
the middle of the posterior border of the parietal and points
in the direction of the parietal eminence.
These separations and clefts, or “false fontanelles,” were
known to Gerdy, Velpeau, Hyrtl (50), and probably other
earlier observers; their origin was explained by Toldt (49, p.
85), Maggi (61, 62) and Ranke (36, p. 59). Ranke, who ex-
amined a large number of skulls of human foetuses and chil-
dren as well as a considerable number of skulls of apes for
these features, has shown the interesting facts that separa-
tions of this nature may extend for a considerable distance
into the parietal; and that, while in man the separations are
very much more frequently posterior than anterior, the con-
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 35 I
ditions are the reverse in the orang, and the anterior clefts and
sutures are much the more frequent. The material used by
Ranke consisted of 162 skulls of human foetuses and infants,
ranging from the eighth to the tenth month in age, and 245
skulls of mostly young Orangs, 8 skulls of young gorillas, II
of young chimpanzees, and 70 of Hylobates concolor of various
ages. The remnants and traces of the “parietal suture” were
distributed among these as follows (36, pp. 59 et seq., 4o et seq.):
“INCOMPLETE SAGITTAL PARIETAL SUTURE.”

“Remnants.” “Traces.”
Anteriorly.
Posteriorly.
Anteriorly.
Posteriorly.
I62 young human
skulls. . . . . . .
245 skulls of orangs.
8 skulls of youn
gorillas......
II skulls of young
chimpanzees.
7o skulls of Hylo-
bates concolor
#:8%
13 (“5.3 %)
I (“I 2.5%)
1 * (in 9. I 9%)
O º -
I3 (in 8.o.2%)
O 4-
O t-
O -
O *-
I (in o. 62%)
O *
O -
O -
O *s
27 (in 16.78%)
O -
* On both sides.
Besides these, Ranke found the incomplete suture ante-
riorly on both sides in a Cynocephalus ursinus and on one side
in a Mycetes seniculus (cases mentioned before).
My own investigations on this incomplete, normal separa-
tion in the parietal bone have resulted as follows: Among 21
well-preserved skulls of new-born to Io-months-old children,
I found it posteriorly in 13 cases (62 %) on both sides, in 3
(14%) on the left side, and in 2 (Io 9%) on the right side.
In two additional cases (skulls of a 3-months and Io-months
child) there were in about the location of the division marked
indentations; in one case only (skull of a new-born child)
there was no trace of it to be seen. In 7 skulls (14 instances)
the division was marked, corresponding probably to what
Ranke calls a “remnant of the parietal suture.” Anteriorly,
I found in seven of the skulls, or one third of the number
examined, five times unilateral and twice bilateral, Smaller
fissures, located between the sphenoidal angle and the middle
352 Bulletin American Museum of AWatural History. [Vol. XIX,
of the anterior border of the parietal. It was not possible to
determine whether all these anterior fissures represented por-
tions of the anterior incomplete separation between the por-
tions of the bone developed from its centers, or were fissures
of other nature.
Traces of the posterior incomplete parietal suture can be
met with in many crania of children of all ages, and Occa-
sionally even in skulls of adolescents and adults. I come fre-
quently across them in the crania of Indians. In children
above one year of age and older subjects we are liable to find,
as already signalled by Maggi and Ranke, the posterior as well
as the anterior cleft filled by an intercalated bone; we will
return to these bones in the succeeding chapter.
There are a few points of additional interest concerning the
incomplete parietal sutures which appear to have not been
mentioned by any author. The two portions of the parietal
squama between which the crevice exists do not unite, when
coming into apposition, in the manner in which the edges of
the other clefts and fissures of the parietal border (v. below)
unite. There is formed at first between the two parts a
squamous articulation, in which the lower part always over-
laps the upper. The obliteration of the fissure proceeds from
its summit, the two portions of the shell uniting by means of
fine bony spiculae, which all have a backward and upward
direction, starting from the border of the 1ower portion. This
border shows occasionally a slight serration.
In all my cases without an exception the incomplete parie-
tal suture was directed towards the parietal eminence.
In a number of instances the suture was traceable further
ventrally than dorsally.
The posterior suture is present, though I do not know with
what frequency, in new-born negroes and, as I mentioned
before, it is not rare in the Indians. I have also seen it in
monkeys (v. Part IV), and in seven very young coyotes, but in
no other mammals.
When an incomplete parietal suture, which is a normal
feature of the foetal and even the young infant parietal bone,
persists into advanced childhood or even into adult life, as
1903.] Ardlička, Parietal Bone in Man and Other Mammals. 353
in the three Bavarian skulls Ranke metations, it assumes the
Significance of an anomaly and a relation to the persistent
complete parietal separation.
But, incomplete parietal sutures are not the only divisions
which may be normally observed in the borders of the parie-
tal during its development. The two elementary parts of the
parietal ossify in rays, which radiate in all directions. These
rays, I have been convinced by numerous examinations, ad-
vance in the osteogenetic membrane not indiscriminately,
but, possibly under well-established influences of the nervous
System and the blood supply, in a definite and quite constant
manner. They constitute several tufts, separated by more or
less marked clefts or fissures. The periphery of each tuft is
composed of many individual rays of bone, and these rays
also are separated on the periphery by clefts or fissures.
These separations between the tufts of the bone seem to me
to be of Some morphological significance and they may be
conveniently termed the primary parietal fissures (reserving
for the intercentral separations the term suture). The nu-
merous minor clefts between the individual rays, which are
of but a very little if any importance, may be distinguished
as the secondary parietal fissures.
The form of the primary fissures in a new-born child is
mostly that of a narrow V, but it may be that of a line. Not
rarely the border of the parietal will show about the mouth
of the fissure more or less deficiency, the result of which is a
Small, triangular or irregular membranous space, a sort of a
Supernumerary fontanel.
Any of the primary fissures may be fully synostosed at
birth, though this occurs more frequently a little later and
Sooner with some than with others. The fissures that are
still present at birth ranged in length in the skulls I examined
from a few millimeters to two centimeters.
As to the exact number of the primary fissures I am not
fully certain; this point has to be settled by further investi-
gations on bones of foetuses obtained at various periods before
birth. There are four situations in which the fissures occur
almost constantly. *
[%une, 1903.] 23
354 Bulletin American Museum of Natural History. [Vol. XIX,
The first and only well known of the slits is situated at
about the junction of the middle with the posterior third of
the sagittal border of the parietal bone. This point, which
corresponds to obelion (Broca), is about 2.5 cm. above the
lambda in the new-born child (Hamy), or about 7 cm. above
the lambda in the adult (Broca). In the adult the location
of the obelion is generally marked by a moderate flattening or
depression of the parietal borders, by a marked simplification
of the Sagittal suture, and by one or two vascular openings,
the parietal foramina. In the new-born child there occurs at
this point either a marked triangular fissure, or a deficiency
in the border of the bone, or, most frequently, both, fissure
and deficiency. The formation has been studied clinically
particularly by Gerdy (44), Barkow (39), Welcker (17), Hamy
(45), Broca (38), and Augier (46), and more recently especially
by Maggi (61, 62). *
When the just-mentioned primary incisure is narrow and
not accompanied by a marked deficiency of the Sagittal bor-
der of the parietal bone, Broca terms it the parietal incisure.
When the slit is wide at its mouth or accompanied by a de-
ficiency in the border of the bone, it forms, alone or with its
fellow of the opposite side, a membranous space, the parie-
tal fontanel, or, as it has been termed by Hamy, the fontanel
of Gerdy. This fontanel occurs, according to Broca (with
whose examinations my own agree), about once in every four
cases of new-born children. Broca properly attributes to
looth, the incisure and the fontanel, the same signification
and the same etiology; they are, however, both represented
as being due to ‘a somewhat retarded development of the
parietal in this situation, due to a more feeble nutrition in
this than in other parts of the bone,’ which theory is hardly
tenable. There are cases in which such a “retarded develop-
ment” may account for the deficiency in the parietal bor-
der; the fissure, however, is distinctly a normal slit of a
different signification.
Maggi’s and especially the still more recent Frassetto's (67,
69, 7'o) contributions to this subject tend to give the “parietal
incisure” the valency of a partial parietal suture, while the
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 355
“fontanel of Gerdy” is likened to the parietal pore in the
Stegocephali. -
The “parietal incisure,” or the fontanel, when this is present,
becomes occluded in most cases within three months after
birth (Broca); exceptionally, however, it may remain open
1onger. I have seen cases where the incisures were marked
at the ninth and twelfth months after birth, and in rare cases
the incisure may last even after this period. In rare in-
stances there is found in adults in this location a suture,
which runs in a more or less vertical direction over a portion
of the parietal. Such a suture, instances of which have been
seen by Otto, Broca, Pozzi, and Hamy (v. Part II), represents
probably in most cases a persistence of a larger portion of the
primary fissure, though it may also be a remnant of a formerly
complete, anomalous, more or less vertical parietal suture.
The membrane which fills the fissure under consideration is
in most instances traversed, at various distances from the
median line or line corresponding to the later-formed sagittal
suture, by a small blood-vessel. As the closure of the fissure
advances, this blood-vessel is embraced by the borders of the
fissure and runs henceforth in a canal, which on the skull is
Rnown as the parietal foramen. Occasionally the part of the
primary fissure between this foramen and the Sagitta1 suture
remains patent, simulating, but not identical with, the sutures
to foramina found in the parietal in many mammals (v.
special chapter on these sutures).
In rare instances, as pointed out by Hamy, a fontanel bone
develops in the “sagittal” fontanel. This bone may unite
with one parietal and appear as a process of the same.
Similar slits and deficiencies as in man occur at the sagittal
point in various mammals, but they seem to be generally
more advanced in obliteration at birth than is the case in man.
Most commonly we find in the new-born animal simply a
greater or 1esser depression at the Sagitta1 point. This occurs
in monkeys and in the carnivora. I saw the bilateral depres-
sion very marked in five tiger foetuses, and somewhat less
pronounced in a number of new-born lions, coyotes, and dogs.
I have no observations on new-born apes. In the ungulates
356 Bulletin American Museum of Natural History. [Vol. XIX,
&
the parietal bone is relatively narrower (especially in Bovidae)
than in the carnivora or primates, and, with the exception of
One young camel, I could find no fissures or fontanels at a
point which would correspond with the obelion.
For parietal sutures terminating at this point, v. Part IV.
The primary fissure next in importance occurs in the pos-
terior border of the parietal between the incomplete parieta1
suture and asterion, commonly nearer or at this 1atter.
The only author in whom I find a mention of this fissure
(though a fontanel at this point is known to Maggi and Fras-
setto) is Ranke, and even this observer refers to it but very
briefly. In Ranke's words (36, p. 65), one of the fissures of the
parietal border “can be quite frequently observed to run, in
a radiating direction, from the point of the postero-inferior or
mastoid angle of the parietal towards the parietal eminence.”
According to my investigations the fissure terminates thus
mostly in the parietals of foetuses and the new-born, but in
older skulls remnants or traces of it are more generally situ-
ated slightly to moderately above the point of the mastoid
angle or asterion. Its direction, as Ranke states, is towards
the parietal eminence.
But there are other points of interest about this fissure.
The feature is quite constant in the new-born infants and for
some months afterwards; I found it, more or 1ess well marked,
and generally bilateral, in 16 (8o 9%) out of twenty skulls of
new-born and infants 1ess than one year old; and I have seen
plain traces of it in skulls of older children. In rare instances
(v. Part II) the fissure may persist into adult life.
The form of this slit corresponds to that of the obelion
primary fissure. Like this latter it can be occasionally
traced, especially ventrally, for a considerable distance tow-
ards the parietal eminence. But, while the obelion fissure
seems to unite by a simple apposition, the Supra-asteric fis-
sure synostoses mostly, if not generally, in the squamous man-
ner of the posterior incomplete parietal suture. The mouth
of the postero-inferior is generally smaller than that of the
obelion fissure, nevertheless it is much more frequently than
the 1atter filled by an intercalated Ossicle.
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 357
The postero-inferior or supra-asteric primary fissure seems
to be rare, if not absent, in monkeys; I have never seen it in
the Specimens that I examined, which, however, did not
comprise foetal material. I found the fissure more or 1ess well
defined in five lion foetuses, two young hyaenas, two young red
foxes, two young Virginia deer, two young sheep, One young
goat, One young Boselaphus, two young camels, and two
young pigs (v. detail list in Part Ix, ‘Divisions to Foramina ’).
Obelion fontanel
Pre-obelic and primary
fissure. fissure.
g i Postero-superior
fissure.
• *
i
i
|
te
º
;
*
- *
- T. - º * Postero-inferior
primary fissure.
i
I
- *
Fig. 31. Left Parietal Bone of a new-born child, showing most of the primary fissures.
This distribution shows that, whatever may be the importance
of the fissure, it is a well-established feature of the parietal.
The sphenoidal fissures of the parietal bone may possibly
belong to the primary slits; they are generally two or three in
number, and are constantly present in the skulls of new-born.
children. Their appearance at this stage is that of well-
marked, open clefts, o.4 to I.o cm. long, directed towards the
parietal eminence. The clefts become obliterated soon after



358 Bulletin American Museum of Matural History. Vol. XIX,
birth. I found them fully obliterated on both sides in a child
Of three months, and on the right side in another chil" of
about the same age. They were still present, though no very
marked, on both sides in a child of about six months, but
were absent in all the older specimens which I examined.
Besides the described, there are several other fissures which
may possibly be primary, and which occur with some degree
of frequency in the parietä1 bones of new-born children. One
Coronal suture.

Metopic suture. ------
Fig. 32. Radiations from the metopic and coronal, suture in a nearly adult
Alces americanus (No. 13,796, A. M. N. H.).
of such marked slits occurs at bregma; two in the superior
parietal border; one I.o to 2.0 cm. anteriorly, and the other
I.o to I.5 cm. posteriorly, to the obelion fissure; and one in
the posterior border between the lambda and the posterior
incomplete parieta1 suture. The slit between the obelion fis-
Sure and lambda becomes much more frequently than the
obelion fissure or fontanel filled with an intercalated bone.
Further observations are necessary to establish the exact
nature of these clefts. (Fig. 31; P1. XXII.)
BuLLETIN. A. M. N. H. Vol. XIX, PL, XXII.
THE LEFT PARIETAL Bone of A New-Born CHILD (vex.TRALLY), SHowing THE
PRIMARY Fissures (SPECIMEN IN THE Collection of the MoRPHological
Museum, CoLUMBIA UNIVERSITY).

FISSURES IN THE PARIETAL BONES OF NEW-BORN AND SLIGHTLY OLDER CHILDREN.

- & “Sagittal Postero- Postero- Sphenoidal Anterior Pre-lambdoid
§: Age Obelion Fontanel” inferior superior angl Fissure Fissure in E. & 1
O. & Fissure. e e ngle in Superior Superior xceptional.
(Gerdy's). Fissure. Fissure. Fissures. Border. B º
I New-born — * both sides both sides both sides &ºm= * &=º
2 & & right sºme * *- both sides *-º *E=º tºº
3 § { both sides s=== both sides *s both sides * -º both sides *
4. é & * both sides *º-E left both sides &º-º-º: *=ºse *
5 § 3. both sides sºme both sides, P both sides left {- *
marked
6 $ & left &= both sides Eº both sides <-º-º-º: both sides . Gº-º-º:
marked (Wormian)
7 6 & right both sides left both sides both sides, smºmº Eº-º
small
8 4 & sº both sides both sides, sº both sides *º both sides (A marked
marked | fissure in 1.
º " . g i bregmatic
9 & 6 *Eº-º: both sides both sides, both sides both sides right * l angle.
marked
IO & 6 right *= both sides ammº both sides P *º-º. *sº
I I & 4 both sides *=sº both sides both sides both sides * sº *
I 2 & 4 left * both sides, * both sides right * sº-
marked
I3 & 4 both sides * both sides, P both sides, both sides *º- *E-3
marked marked
14 || New-born, or &=e both sides &=º right tooth sides * 3-ºxºº. —
a little later
I5 Ist or 2d mo. left right both sides e== both sides sº * *gº
16 || abt. 3 mos. s=ºse *== * * -º- tº-º * * sº
17 abt. 3 mos. both sides * both sides * left &= --> º-º ſº-º-º-º:
On both sides
I marked
18 abt. 6 mos. &=º * P *g both sides =º wº- *::: *
19 | abt. 9 mos. both sides gº-ºº: both sides | both sides 4- tº- * - ::::::::::::
Squamous
Suture.
20 l abt. Io mos. both sides &ºme both sides, * *º gº sºme * -
marked
2I abt. Io mos. both sides * both sides * tºº- sº-º- * •º
(21) || 13 at birth, 8 both sides || 4 both sides | 16 both sides || 4 both sides | 16 both sides | 2 both sides | 3 both sides
8 birth to one = 36 /o = . 19 Żo E ºf O = . 19 Żo = 76% = 1 o żo = 14 %
year 3 left side 1 right (in 7 pro- 2 left side (in one espe- || 2 right side
= 14 % = 5 % nounced); = Io 9% cially pro- = Io 3.
nounced); I left side
3 right side I right side I left side = 5 %
= I4 /o = 5 /o = 5 %
Total percent. Absentº in aſ ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ||Present in aii ' ' ' ' ' ' ' ' ' ' | " ' ' ' ' ' ' ' ' '
of occurrence the cases new-born and *
above 2 mos. up to first
or second
% % ºth.
66.7 % 24 8o 33.3% I Zo
~ £of the = #bt + of = # of the or # $f the = #;
CaSeS. the cases. cases. . .] cases. . . .Absent after. 24% 14 %
; : :"... :: * :::: #3th: ; : = abt. # or abt.
...] ... : :": {* : *::... ºlº I in 7 cases
190 3.] Ardlička, Aarietal Bone in Man and Offer Mammals. 359
The following list shows with what frequency and in what
combinations I found the various slits in my series of 21 skulls
of new-born and young infants."
If we can judge from some of the persistent partial parietal
divisions, some, if not all, of the last described slits occur also
in the monkeys. In lower mammals relatively pronounced
fissures are not
infrequently seen
in the very young
in or near the
angles of the pari-
etal. Thus a fis-
sure in or near
the supero-ante-
rior or bregmatic
angle of the pari-
etal was found in
one young fallow
deer, four young
Indian buffaloes,
and One young
Boselaphus. Fis-
sures in or a short
distance above
the spherloidal
angle were noticed
in two young
hyaenas, one
Posterior,
normal,
*----incomplete
parietal
Sulture.
Y--- Posterior inferior
primary fissure.
young sheep, tWO Fig. 33. Posterior third of the left parietal bone of a child
youngfallow deer, ... .º.º.º.º.º.
One young Bos inclosures (Morphological Museum, Columbia University).
£ndicus, one young Boselaphus, one adolescent pig, one young
hippopotamus, and in some, mostly young, Seals and Zalophi.
Fissures in or just below the superior-posterior angle of the
bone were observed in three arctic foxes (adults), and one
young Virginia deer. The fissures in or above the postero-
* Specimens in the Morphological Museum, Medical Department of the Columbia
{Jniversity, New York City.

360 Bulletin American Museum of Matural History. [Vol. XIX,
inferior or mastoid angle have already been mentioned. Some
of the slits seem to be characteristic of certain species of
animals, but this point must be settled on large Series of
proper material.
The constancy or frequency of the various primary and
primary-like parietal fissures in man and mammals imparts
Lambdoid to these formations
Sulture. -- - - - --S a peculiar interest.
Apparently these fis-
sures are not casual,
meaningless fe a -
tures, or mere acci-
Sagittal suture. --———— - dents of growth.
Some of them may
[7 loe due to the mech-
º anism of growth of
º the parietal, but
some are undoubt-
Cºl. edly regular features
** of the development,
the manifestations
w of some as yet not
understood law of
the development of
the bone. In view
Metoriº. -------- of the constancy or
frequency and a
definite location of
the fissures, the tufts
# 34. Radiations from the cranial sutures in an adoles- of bone which con-
cent Black Bear (No. 6639, A. M. N. H.). dition them assume
the rôle of regular constituents, of subordinate elementary
portions, of the main elementary parts of the parietal.
The numerous secondary parietal fissures need only brief
mention. They are present on all parts of the border of the
older foetal parietal, constituting the parietal comb. The
obliteration of these crevices presents one little peculiarity.
As the rays of the growing bone reach its limits, and possibly

1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 361
somewhat before this, the Osseous rays meet with increasing
resistance to their advance. Not being able to progress freely,
the ends of the rays grow laterally, thus spreading and ap-
proaching each other. A close approach between these ends
is effected before the proximal part of the crevice has been
filled, and a union of the ends taking place, this proximal part
of the crevice is converted into a foramen (v. Fig. 33). The
foramina thus formed in the parietal border transmit no
blood-vessels and soon disappear. The cranial sutures are
partly due to the interlinking of the rays and secondary fis-
Sures of the parietal and other bones.
The union of even these secondary parietal fissures may be
retarded, in which case the parietal border will appear full of
incisures, as in the bear and moose shown in the following
figures. (Figs. 32, 34.)
VIIIB. WoRMIAN OR FONTANEL BONES IN THE LOCATIONS
OF THE INCOMPLETE PARIETAL SUTURES AND
THE PRIMARY PARIETAL FISSUREs.
The formation of intercalated bones in the “false fontan-
els” of the parietal has been known to Hyrtl, Ranke, and
other observers, especially Maggi, and has already been partly
referred to (v. Part vTIIA). The bones belonging to this
category are usually of moderate size and oblong, but do
not differ materially from other Wormian bones, and cannot
be distinguished from these except by their location. Occa-
sionally, mainly on account of multiplicity and similar shape
of the Wormians, all effort at separation of the fontanel
bones must be abandoned. The recognition of the fontanel
bones adds considerably to our proper understanding of the
subject of intercalated bones, and diminishes very much the
numbers of the purely accidental of these ossicles.
An examination of 45 complete skulls and Io 5 detached
calvaria of whites, all with still patent cranial sutures, en-
abled me to find intercalated bones in the 1ocation of the in-
complete parietal sutures and also in that of all the fissures
* (62); also Frassetto (69).
362 Bulletin American Museum of Natural History. [Vol. XIX,
-#
mentioned as primary, except in the antero-inferior and
antero-superior angles.
The 45 complete skulls comprised 21 males, 12 females,
and 5 children; there were among these 45, 14 without any
Wormian; of the 31 remaining there were 17 (8 males, 8 females,
I child) with one or more of the “fontanel” ossicles. There
were, in total, 33 clearly discernible “fontanel” bones, beside
which Io, in the same 17 and other skulls, were doubtful.
The distribution and combinations of the 33 bones were as
follows:
& g left. right
§ A Wormian in the mouth of the ant, incompl. par. Sut. I 4, QF in 5.56 % of the
£ 6. º $ 8 & 8 & & 6 post. & & 4 * & & 4 5 3, $ & 8.9 O
'y & & ... . & 6 . “ post-inf. prim. fiss. 7 6, ‘‘ ‘‘ 14.4 % rie-
Or & & & & { % post-Sup. 6 & & & 3 3, £ 4 & 4 6.6 % |Pa
& is & 6 & 8 & & & & 6 & * 1 & 4 & 4 {{ { { tals.
6 pre-lambdoid I I, % U
and 8 in I
and y in 2
'y in r
and 6 in 3
and e in I.
Combinations:
0.
0.
8 and
8
y
Fig. 35. Right Parietal Bone of a Southern Utah Cliff-dweller (child),
showing remnants of anterior and a posterior parietal cleft; the posterior
indentation is filled by a Wormian bone, the anterior by a spur of the
frontal (No. 25, Hyde Collection, A. M. N. H.).
In the Io 5 calvaria, with only parts of the parietals present

1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 363
a was seen clearly in 3 cases and in 4 others was doubtful;
e was observed in four instances and a preobelic bone in two
instances. The 8 and y bones could not be examined in
this series; neither could a low situated a or y have been
detected.
The fontanel bones are by no means restricted to whites.
They are quite frequent in the Indians, but seem to be rare
in the negroes. As to other ethnic groups I have not enough
proper material.
In numerous instances the mouth of the anterior or pos-
terior incomplete parietal suture, or that of a primary fissure,
is occupied by what appears to be a spur or process of the
neighboring bone. In some of these instances the process is
undoubtedly a partly attached Wormian. The following illus-
tration shows a parieta1 in which the remnant of the anterior
incomplete suture is filled by a process of the frontal, that of
the posterior suture being filled by a moderate-sized Wormian.
(Fig. 35.)
IX. PARTIAL DIVISIONS OF THE PARIETAL Bon E RESULTING
FROM A MECHANICAL OBSTRUCTION IN THE OSSI-
FYING BONE, OR, DIVISIONS TO FORAMINA.
The divisions coming under this title form distinctly a class
of their own. They have a totally different etiology and sig-
nification from the sutures and fissures considered in the
preceding chapters. They occur typically as fissures, or,
more frequently, as nicely serrated sutures, which extend
between a border of the bone and a foramen situated at some
distance from the border.
Divisions of this class are very rare in the parietal bone
of man and the primates, but are almost constantly present
in some lower mammals. They are not restricted to the
parietals, but occur in many other bones of the skull, par-
ticularly in the temporal squama and within the orbit. 2
They are closely related to, though not identical with, the
divisions which in man are so commonly observed to pass-
from One of the sutures within the orbit, or from the
364 Bulletin American Museum of Natural History, [Vol. XIX,
malo-maxillary suture outside the orbit, to the infraorbital
foramen.
The only location on the human parietal bone (and also on
that of primates) where a suture or a fissure between a fora-
men and the border of the bone occurs is at the parietal
point or obelion. The division, when typically present, which
is very rare, connects the sagittal border of the bone and the
parietal foramen. It should not be confounded with a simple
incisure or suture at this point, though at times a distinction
may be very difficult.
In lower mammals by far the most frequent, though by no
means exclusive, location of a suture or fissure to a foramen
is in the posterior half of the lower third of the parietal. (I
state on the appended list the approximate location of every
division found in the different animals.)
The location of divisions of this class, particularly on other
bones than the parieta1, is occasionally peculiar to a single
species of animal and may serve as an additional sign of
differentiation of the species.
In form the sutures or fissures to foramina are generally
straight, or but slightly curved. The serration, when present,
is fine and regular. The fissure and suture are seen to be
absolutely equivalent, for in many specimens on One parietal
bone we see a fissure, and on the other, in the same location,
a Suture.
In length the divisions under consideration range from one
or two millimeters to as many centimeters. (The detail list
gives the measurements of most of the divisions I found.
The majority of the sutures and fissures, it will be seen,
range in length from 4 to 8 mm.)
In some cases the division, although running directly to-
wards a foramen, will not quite reach it. Apparently a part
of the division, proximal to the foramen, has in these cases
become obliterated. This view is substantiated by the fact
that complete divisions can be found in the same locations to
similar foramina in other individuals of the same species.
The whole division may be found ossified; but I have never
seen a case in which the distal extremity (from the foramen)
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 365
of the division would be occluded alone. Occasionally we
will find a fissure or a suture in the border of a bone, without
a foramen, but in a location where in other individuals of the
Species, or perhaps on the other side in the same individual,
Occur divisions from foramina. In such a case it is quite safe
to conclude that the foramen, from which the division origin-
ally ran, became occluded earlier than the division.
The ossification of fissures and sutures of this class pro-
ceeds regularly from the foramen towards the border of the
bone in which they occur, hence in the direction of the orig-
inal ossification of the bone.
The obliteration of the sutures and fissures to foramina
may occur very early, but often these divisions are patent
even after some of the regular cranial sutures have united.
They seem often to become occluded at about the same time
that the cranial suture to which they lead is thus affected.
The number of the divisions to foramina on the same bone
in the same species is not strictly limited. There may be but
One, or several such divisions in one bone. As a rule there is
but One suture or fissure to any one foramen; on the other
hand One division may lead to more than one foramina. The
frequency of the divisions stands in direct relation to the
number of larger foramina present on a given bone in a given
species.
The nature of the openings from which a fissure or a suture
passes to the border of the bone cannot always be ascer-
tained on a skull, but the greater majority of them seem
to be vascular foramina. It is probable that a division may
also proceed from a nerve foramen.
There is one more feature about the divisions under con-
sideration which deserves a special notice. It can be fre-
quently seen that the distal extremity of the suture or fissure,
that is, the part nearest to the border of the bone, is filled
with or covered by a spine, which proceeds from the adjacent
bone. (In divisions in the lower portion of the parietal bone
the spines proceed from the temporal squama, while in divi-
Sions of this latter the spines proceed mainly from the parie-
tal.) The spine may simply occlude the extremity of the
366 Bulletin American Museum of Natural History. [Vol. XIX,
fissure or suture; or it may cover a large part of the same;
or, finally, it may outwardly take entirely the place of the
division and reach to the foramen. The spine is usually
broad and deep at its base, becoming gradually narrower and
more superficial towards the extremity.
The tendency to the formation of these spines is much
more marked in some species of animals than in others.
When they occur in man, they usually cover a vascular
canal.
The etiology of divisions that lead from foramina to the
border of a bone is different from that of the anomalous divi-
Sions, as well as from that of the primary fissures of the
cranial bones. The foramina from which fissures or sutures
are seen to pass are very early formations, and date in all
probability to the membranous condition of the bone. If we
examine the growing bones in man or animals, we find the
openings to present the following characters: The proximal
part of the foramen—that is, that part which faces towards
the center or body of the bone—is well defined, rounded, and
Smooth. The distal parts of the opening are more or less
deficient, and this deficiency continues to the border of the
bone. In very young specimens the defect in the border will
loe a cleft with diverging sides. On little older subjects the
walls of the cleft are seen to approach. In still older speci-
mens the walls have come into apposition, and from the now
completed foramen a fissure runs to the border of the bone.
Still later, the fissure gradually unites, or, the process of
primitive Ossification diminishing, it remains permanent. As
the bone continues to grow, serration may develop in the
fissure and transform it into a suture. The approach of the
walls of the cleft proceeds in most cases from the foramen
downward. Where the approach of the walls of the cleft had
loeen slow, a compensatory process or spine is liable to develop
from the margin of the adjacent bone, and more or less fill
the existing cleft. The process or spine plays a similar rôle to
that of Wormian or fontanel bones.
All the foregoing facts point to the following conclusion as
to the nature of the divisions under consideration: the fis-
1903.] Hrdlička, Parietal Bone in Man and Other Mammals. 367
sures and sutures that run from foramina to the border of a
bone are not characters or properties inherent in the bone,
as were the divisions considered in Part VIIIA of this paper.
They are acquired,
consecutive charac-
ters, the results of
mechanical obstruc-
tion, which early de-
veloped blood-vessels
(or nerves) offered to
the Ossification of the
bone. They differ from
the anomalous divi-
Sions in that they are
independent of the
number and location
of the centers from
which the bone de-
velops.
Squamous
SUlture.
foramen.
L.
Fig. 36. The posterior parts of the temporal squamae
of a young Virginia Deer & º
ing different stages of the formation of a fissure from a
Posterior superior
angle. Squamous
# W Suture.
§
\ }
\ }
\ 1
R.
No. 8121, A. M. N. H.), show-
Of the following figures the first shows the process of for-
mation of a fissure to a foramen, as actually observed on the
two sides in the temporal bone of a young Virginia deer.
(Fig. 36.) The second figure shows the middle two thirds of
sy.”
Fig. 37. The middle two thirds of the right tem-
poro-parietal suture and the squama underneath, in
an adult native dog from British Columbia (No.
13,773, A. M. N. H.), showing an irregular defect in
the É. (A), now filled with a small separate bone
and a marginal defect in the squama (B), now filled
with a portion of the parietal bone. Both defects,
and probably the underlying foramina, are remnants
of a former fissure in the squama.
the right temporo-pari-
etal articulation in an
adult dog. In this case
an apparently large slit,
a short distance beyond
which is situated a small
foramen, has been filled
by a Wormian bone and
by an irregular rounded
piece of bone now united
with the parietal. (Fig.
37.) The third figure is a
Schema of the several varieties of divisions and spines from
and to foramina, which can be observed in full-grown indi-
viduals.
(Fig. 38.) The fourth figure shows a division in an


368 Bulletin American Museum of Natural History. [Vol. XIX,
oryz, which is continued from a notch in the parietal border
to three parietal foramina. (Fig. 39.)
The appended list gives in detail the various divisions
found in the parietal bones of different mammals below man
and monkeys. The extent of the material made it impera-
tive to use certain abbreviations in the records; the index of
the abbreviations is given at the head of the table.
$– 3–
* -----
Fig. 38. Divisions and Spines from and to Foramina on the Parietal, Tem-
poral, and other Cranial Bones in Mammals and Man. 1, simple fissure from
a foramen to the border of the bone; 2, suture; 3, fissure and a small spine ;
4, fissure and a spine of moderate size; 5, complete spine; 6, incomplete su-
ture; 7, incomplete spine; 8, double spine.

Af
.2
Lambdoid 2 sº
Suture. / *Aaſha
Temporo
.# &=º- arietal
* ~~ —— P
N.
SIlture.
N.
% S
he
Fig. 39. The postero-inferior portion of the parietal bone of an
Qryx (No. 13,552, A. M. N. H.), showing, S, a spine filling a cleft in
the border of the parietal bone, and above that a suture, running to
three superimposed foramina.
FISSURES AND SUTURES TO FORAMINA IN THE PARIETAL BONE
IN ANIMALS.
Abbreviations.
f = linear fissure.
ff = multiple linear fissure.
f sp fissure with a spine in its mouth.
ending in a foramen.
suture, incomplete, not ending in a foramen nor directed to it.
incomplete suture directed to a foramen. -
& &
to a foramen.
first or upper (coronal and 1’d) third of the suture.
middle third of th
“ third fourth
S -
S d -:
s f :
S Sp F. * &
Sp. = spine.
Sp f – “
# = at the end ºf the
# = & 4 .."
II]. = at middle
r == right.
1 = left.
v. or vert. = vertical.
h. or hor. = horizontal.
o, or obl. = oblique.
I. O = I.o cm. long.
lo. S. = both sides.
bil. = bilateral.
with a spine in its mouth.
e Suture.
ſº § {

From Coronal
Suture.
From Sagittal
Suture.
From Squamous
Suture.
From Ilambdoid
Suture.
Carnivora : Ursidae.
... a. Iſleſ 1Ca.1111S.
(I) 3762,” adol.
{:} 5 O45,
3) 14os3, ad.
§ 5044, adºl.
5) 3767,
6 49, 39.
7) 7376,
8) 6639, young
9
O
{
(
(
{
( 6 é &
::) #. adol.
§ 858o, ad.
(13) 7374, ad.
14) I T 167, adol.
I 5) 62.83, “
I6) 2006, “
17) 6292, ad.
18) I3964, adol.
I9 28o, ad.
(20) II 6, “
s
*
ff, b. S., o.2 to o.4
*-
ff, b. S., o. I to o-3
s
I
O
º
§
3,
s
Sp f, o.3, r, vert., §
sp. f, o. 2, r, v. near
lamb. suture.
Sp f, o.2, r, v, near
lamb. Suture.
sp f, o.3, r, o, 3
=
*=m.

Black Bear
(20)
Multiple fissures | Multiple fissures in 2
young and I adol-
in 2 young.
escent.
Short spine, to a
foramen, in the
last # of the bone,
in 3, 2 adolescents
and I adult.
U. maritimus.
(I) No . adol.
–
-
-
2 5o, aq91. * ;
3) 503 I, spºº, r., o.5 from &= -º -
g-
(4) 5og2, ad. - *-m s f, o. 2, 1, near -
lamb. s.
{3} 56, : * * S f, O-3, T, § *º-
(6 55, , , * *- sº-mº * *
(7) 290, ... *ms * *m-. *
(8) 14os4, . * * *- *-*.
(9) IIos I, * * *m, *
ro) to 240. “ *m-sº -- &ºmº *-
Polar Bear A spine, in I, into * Short suture, to a --
IO the parietal on foramen, in the
right near breg-
T ma (adolescent.)
last # of the bone,
in 2 adults.
* All the specimens here referred to are from the Zoëlogical Collection of the American Museum of
Natural History, New York.
369

Frºg $ºnal Frog Sagittal From iºnous From Hºbdoid
titlife. 11ture. 11ttire. 11ture.
Felida
(I) F. :
I ) I3904, a CIOI. q=mºsº -º- * *m.
(2) º ºf *-ºs * — . -
(3) 8355, young - * f, o.2, b. S., into the *
( 6 £ 4 -- mastoid angle.
4) O259 mº. * *- º-
§ foetus at term. * * *-*º * *mºmº:
(6) “ “ “ * * f, b. S., o.3, into º-
§ & & 4 mast. angle
(7) 6 tº gº-ºº: *E* f, b. s., o.2 & o-I, *º-
& into mast. angle.
(8) “ “ “ * = *m. f, b. S., º into tº-
{3} . . . f, o.8, r. § - mast angle. *mº,
(Io tº & tº £ tº & --- * f, o.4, b. i. 1nto - -
mast, angle.
Lion A. fissure, in . I *=º- In 4 foetuses and I -
(Io) ſº . iº young a i. in
.*.* 3: ::::::::::::::::::
parietal bone.
F. tigris.
(I 6I. ad. * * *ms *
{: ăş. . - * * *
3 * --- * * * *
{} 62, “ - --- *-*. *
5 298, near ad. * - *=mºs. º-ms-
(6) Ioss6, ad. º-º-º: *-ºs. *s-s *
{ § ) foetus at term. ** * *...* º-
(9) & 8 £ & & & – – – –
(Io) & & { { & & - *mºmº * * *
Tiger *º *- * *
IO
F. onca.
(r o: adol. * * *-** *
2 293, * - * *
3) 68, . * -- *- *
42 6354, . *ms * ***mº -*.
5) Iro86, * * *ms *m.
6 64, & & -* *º-sº *m. *
7) IIo85, near ad. *mºn * *-*. **
§ 6246, ad. * - *-** *
9) IIo83, near ad. * * *== *
(ro) IIo84, “ &mº --- * *
Jaguar * *== *-*- -
(ro)
( 6: concolor.
I 295, young *E* smm. *m-º. *
2 1333, adol. *gg * ** * *
3) 6249, Eºmº *-*. * **as
4) I 323, ad. *=mºn * * *me
5) I 33 I, near ad. * * *-ºs- | *
º I 339, *= * º- | *
7) 6677, ad. * *=ms. f sp, o.8, 1., # *sºme
(8) 1337, near ad. ** &mºmº * *s
(§ 1336, adol. ** *m-. f sp, o.5, r., # *
IO) I 34O, * * * *
(II) Ioz 59, “ * -*. ** *
(I.2) 1338, ad. *º *º- * == —
(13) I327, adol. ºmº sm-mm- * *same
(14) II 7, ad. &mºmº *º *=== *
(15) 5034, adol. -- *bi; 1, obl., fr. s, 1.5, r., sq. to lamb. *
O Oeil Oil.
Puma «E-º lm I, adolescent, In 2 spine and *E*-
(15) a suture to a fora- fissure in the last


men, on left, from
obelion.
#: in one a suture
separating a por-
tion of the mas-
toid angle.
370

From Coronal
Suture.
From Sagittal
iiture.
From Squamous
Suture.
From Lambdoid
Suture.
F. pardalis.
I4022, near ad.
I 3960, & 4
IOO'73,
Iosoz, adol.
9, near ad.
2Ioo, a Cl.
354, adol. .
6248, near ad.
5938, ado1.
IIo39, “
(
11) 4318, adol.
I 2) 5369, ad.
13) 6.25o, adol.
I4) 6406, “
I5 352, ad.
I6) 5518, near ad.
17 72, adol.
18) I3917, “
I9) 2087, near ad.
A suture, slightly
s
serrated through-
out, Sq. at
pterion over whol
r. pariet. and o.8
over 1. par.; (v.
Part V.
f
T.
29) I 3999, Young
Ocelot
(20)
In I
a complete
vertical division of
the right and in-
complete division
of the left parietal
bone.
F. canadensis.
I 349, young
237,
I35 I,
I343, adol.
1962, “
& 4
:
i
§ {
6420, ad.
:
;
6
I
3
4.
5
y
I352, adol.
{
I
I
12) 8624, near ad.
I 3) IQ53,
I4. 7o, ad.
I5) 2443, near ad.
I6) 2851, ad.
I7) 4606, near ad.
at the
f, o.8,
neight of the tem-
por. ridge, a de-
pression towards
obelion.
s
I8) 1958,
I9) IgGI, & 6
20) 21:87, ad.
Lynx In I adol. a sepa-
(20) rated segment of
a fissure, on left,
along the tem-
poral ridge.
Felis catus.
1) 3778, ad.
2) 3799, near ad.
3) F. gomestica, 3778,
3.
§ F. domestica, 71, ad.
5) & & & &
I963,
ad. e
(6) F. domestica, III.5.1,
near ad.
(7) F. domestica, 11152,
3.C.
(8) F. domestica, 1964,
near ad.
(9) F. domestica, Io.289,
3.Ci.
(Io) F. domestica, I 1266,
young
Cat, wild and domestic
- I O
=
–
–
–
–
–

37 I

From Squamous
From Coronal | From Sagittal From Lambdoid
Suture. | Stiture. Suture. Suture. --
Hyaenas. - - =
(1) H. macul., 8304, v. - -- f 1. o.6, r. o.8, f, small, b. s., o.6
young curved, , in the above asterion
Sphenoidal angle;
a small fiss. on each
side in the mastoid
angle.
(2) H. macul., 971, young - - f Io.3, ab. Sphen. -
- angle.
§ H. : 615, adol. - - - -
4) “ str. 1544, n. ad. - - - -
(5) “ “ 67, ad. - -- - -
Hyaenas - - In I young a fissure | In I, young, a
5) into the sphenoidal fissure on both
angle, in another | sides slightly
young ... slightly above asterion.
above it. In 1
young a fissure
into each mastoid
- - angle.
Canidae.
sº famil., very young
& 4 4 tº & 4 & 4
& 4 & & & 4 4 &
& & * { & 4 4 &
) C. famil., 1203, adol.
} & & “ II or 3, ad.
§ { 4 & 78, adol.
} II IoS, ad.
& 6 “ 408, ad.
} C. f 13681, ad.
) C. fam., II5, ad.
§ { 77, tº ſº
} C 7 { {
. Brit. Col., adol.
“ “ (13773),
=
=
=
=
Vulpes lagopus.
I O2O7, a Ci.
82. “
(I)
2) y
3) Io 227, ado1.
4) IoI 7o, ad.
5) IoI 73, ad.
6) Ioé91, “
7) Io 228, near ad.
(8) IoI 75, ad.
(9) Io 228, near ad.
(Io) Io 232, ad.
-
-
s
f, r., o.3, sup-post.
angle, continues on
interpar. for o.3.
depression, in same
1ocation, on left.
depression, in same
location, on r.,
ending in a min-
nute foramen, o.4
in toto.
i
Arctic Fox
(Io)
In 3 a depression,
or a fissure, in the
1ambdoidal angle
of the parietal.

Vulpes fulvus.
64I3, young
6412, .
6369, t
(4) 3796,
(5) 6415, .
º II.8op,
7) 6414,
8) 3749, adol.
9) 4279,
(Io) IIoë6, ad.
s
s
=
s
f, small, into each
mastoid angle.
f, small, into each
mastoid angle.
s
=
Americº fied Fox
In 2
small *
each mastoid an-
yOung a
IC
fissure in
gle of the parietal.
-
372

From Coronal From Sagittal From Squamous | From Lambdoid
Suture. Suture. Suture. Suture.
Canis lupus gris.-alb.
{:} III, adol. *- *º --> - º
2) ad. *- -* -* º-
( 3 2384, “ *- -> -: *-
4) 4609, “ *- - - *-
5 7 6, & & - -* - -
6) 458, “ - -*se - -
7 II 2, n. ad. - -º - *-
8 481, ad. - - - *-
(9) 5381, ado1. - - - e-
(io) 22:47, ad. *- -º- - *-
Gray Wolf * -* -* *-
&CŞ -
Canis latrans.
(1) very young * - - b. s. depression,
abt. m., run-
ning towards
the eminence.
(2) “ & & * -ºs - b. s. depression,
abt. m., run-
ning towards
the eminence.
(3) “ & & =- - - b. s. depression,
abt. Im., run-
ning towards
t the eminence.
(4) “ “ 9582 *- 1., f, o.7, nearly vert. - b. s. depression,
# abt. Im., run-
ning towards
the eminence.
(5) young --- - - depression, b. S.,
& - n. middle.
(6) “ 14489 * traces of I.I. obl. f. -ms depression, n. m.,
on r., #, and of a f. marked.
4 & o.45, 1..?
(7) I4488 * depression ov, both - º-
pariet's, beginning
6 & at middle.
(8) * - *me marked depres-
sion on each
side, fr. m.
towards emi-
11611Cé.
(9) adol. *- -- -* -
(Io) a C1. &= - -*. - -
{:} 2846, near ad. =- -ms- -* -
12) 3753 ad. =- - - -
I3) 5383, adol. *- - - *-
I4). 5385, near ad. - - - --
I5) 3739, ad. - -* - -
Coyote *- Fissure, in the post. - A depression
(15) # of the parietal, probably the
in 2 young. remnant of a
fissure, about
the middle of
the occipital
border of the
parieta1, in al-
most all young.
Carnivora. Multiple fissures | Multiple fissures in Fiss. in sphenoidal Fissure, above as-
(195) in 2 black bears, 3 black bears; angle in 2 hyaenas; terion, in r
young; Suture to a foramen Spine to a foramen young hyaena;
A spine in I adol. in I puma; in 3 black bears; Depression, at
polar bear; Segment of a fis-1 Suture to a foramen | middle, in 7
A fissure in I lion
foetus.
sure in I lynx;
Fissure or a depres-
sion in the lamb-
doid angle in 3
arctic foxes;
Fissure from obelion
11.1 2 young COy-
Otes.
in 2 polar bears;
Fiss. in mastoid an-
gle in 5 lions, I
hyaena, 2 red foxes
(all young).
Spine and fiss., post.
+, of par., 2 pumas.
Separation of part
of mastoid angle,
I puma.
Division of whole
parietal, r ocelot.
young coyotes.
373

From Coronal
From Lambdoid
From Sagittal
From Squamous
Suture.
Suture.
Suture.
Several small in-
cisures in the
squam. portion
which underlies
the frontal.
s
--
s
f, b. S.,
angle.
sphen.
–
o.9 f. On each side, #
o.4 f. on each side,
just before this,
o.4 f. on each side,
beyond m.
=
s
–
*===
f,
C 2, r., post -
inf. angle.
=
=
small f... in each
mastoid angle.
In
2, yOting,
fissure in the
mastoid angle.

f,
b.s., ab. mas-
toid angle. -
4-ºmº-
Suture.
. Ungulata.
(I) Ovis tragelaphus,
Io 7o 7, V. young
(2) Ovis tragelaphus,
6360, young
(3) Ovis musim, 6294,
3.CiC) i.
(4) Ovis montana, 14oo4,
3.Ci.
(5) Ovis musim., 6233,
adol.
(6) Ovis P 6358, ad.
( 4 & P 8 § {
(8) “
ad.
(9) Ovis tragelaph, Io26o,
f 6238,
tragelaph, Io.261,
(Io) o: frage, II of 9,
a ClOl.
(II) Ovis P 5028, ad.
{:} Ovis aries 6361, ad.
(13) Ovis aries, Io.262, ad.
I4) £ & “ I4083, &_&
(I5) “ P., v. young
(I6) “ stonei, ad.
(I7) “ stonei, ad.
IIo52
(18) Ovis stonei, ad.
I 27 Ig
(19) O. montan., 13793,
near ad.
(20) 26232, young
#
7 f., b. S., o.3 to o.5
=
2 sp. to for., #
sp. f, small, r., á
f for, r., o.3, near
aster.
f for 1., o.7, near
*
f, 1., o.4, m.
;
Sheep
(20)
Several fissures in
I young.
Fiss. above each
sphenoidal an-
gle in I young.
Multiple fiss. in I
young.
6 fiss. in I young.
In I, a fissure at
TITIC!.
In 2 a spine to a
foramen.
In I a fissure to a
foramen.
(I) Capra res., 2074, v.
young
(2) Capra P, Io'ſ 28, v.
young
3) Capra P, 6237, young
4) & £ P 6236, { {
(5) Capra angora, 8360,
yOung
(6) Cºra angora, 6359,
a Ci.
(7) Capra angora, Io 268,
3.Ci.
(8) . Capra angora, 8354
3.Ci.
(9) Capra angora, 2083,
3.Ci.
(Io) Capra 2, ad.
f for, 1., o. 2, §
f for, I., o. 2, §
s f, r., o.3, #
Goats
(Io)
In 2 young a fissure
to a foramen; in
one adult a suture
to a foramen, all
in last + of the
parietal.
In
I a fissure
on each side in
the mastoid
angle.
374

From Coronal
From Lambdoid
From Sagittal
From Squamous
Suture.
Suture.
Suture.
Suture.
Cervidae.
Alces amer.
(1) 6408, near ad.
(2) 3796, adol.
Cervus canadensis.
1) 6351, young
3 209, ad.
3) 5047, adol.
4) 368, near ad.
Rangifer groenl.
I) 14237, ad.
2) 14233, “
3) I4239, young
Rangifer tarandus.
I) 5035, young
2) 51.41, ad.
3) 3460, near ad.
Elks and Rangifers
(12)
=
=
sp f, b. S., #, large,
on left double.
s f, r., o.3, §
=
=
—

=
In one elk a spine to
a foramen, in the
other a suture to
a foramen, both
in the last 3 of the
parieta1.
Dorcelaphus hemion.
§ 13993, ad.
2) II IO9,
3) 12792,
&
&
(4) III.42, near ad.
{3} III.43, adol.
3 II II6, ad.
7) III.4.1, adol.
8) III 18,
(9) II 139,
(Io) IIII.4, near ad.
a,
d
é &
=
*
s
s
Sp f, r., o.6, #
3 small Sp to for.
on 1., I on right.
sf, I on 1., 2 on r.,
small, 3.
sp f, small, 1., 3.
sp f, r., á
sp f, b. §, #
2 sp f on r., #
f for. on 1., sp f on
T.,
s
s
Dorcelaphus.
(Io
Spine to a foramen
in 6;
fissure to a foramen
in I;
suture to a foramen
in I.
Cervus elaphus.
(1) 13911, v. young
2) Io'ſ 13, young
}} Ioo76, ad.
=
=
f, 2 on 1., I on r., á
(o. 2 to o.4).
–
4 141, near ad.
2 sp f., Small, on 1.,
(5) 142, ad. mº- *ºn 3 # f, small, on r., º
Red Deer - - Spine to a foramen *mº
(5) in 2.
Fissure in I young.
375
From Coronal
From Lambdoid
From Sagittal
From Squamous
Suture.
Suture.
Suture.
Suture.
Cervus virgin.
(1) Iozoö, adol.
(2) I4084, “
(3) 3764, near ad.
(4) 3766, ad.
(5) 8363, near ad.
(6) 3798, v. young
(7) 11144, ad.
(8) IIo 28, ad.
(9) 3777,
(Io) 7368, “
(I 1) 812, v. yºung
(12) 2838,
(13) 2078, young
{ & 4
§§ Io 29 O,
I5) Ios I4, adol.
ff, o.1 to o.3, b.
s. of bregma.
a number of
small, f on both:
sides of bregma.
ff, on both sides of
bregma.
f for, b. S., o. 9, §
f, 1., o.7, partly oc-
cluded, #
f for, o. 2, 1., near
sphen. angle.
f for, o.5, 1., #, on r.
a depression.
f, o.3, in each mas-
toid angle.
r. sp f for, #
f for, b. S., o.8, #, sp
in base; on r., for.
obliterated. .
sp and depression
to for. b. S.,
depression to for.,
. S. 2.
(depression.)
(depression.)
(depression.)
(depression.)
sp and depression,
b. S.,
b. S., marked
cleft, above.
mastoid angle.
Virginia Deer
I5
Multiple fissures
in 3.
Fissure in 2; fiss.
to a foramen in 4;
depression to a
for. 6; spine and
depress. to a for.
2; spine and fis-
sure to a for. I.
In I -.
In I young a fis-
sure in mas-
toid angle, in I
y. a fissure be-
low upper #.
Cervus axis.
(1) III65, v. young
{:} I3961, young
3) I of Io, near ad.
(4) 3765, ad.
(5) Ioss3, ad.
=
=
f, b. S., o. 2, 3
depression, on left
traces, on r. deep;
connects two fora-
mina-vascular.
Axis Deer
(5)
In 1. a fissure on
poth sides; in 1
a depression.
Cervus dama.
{r} 6365, v. Young
(2) Ioz14, f, o.4, r., m. -º-, s, b. s., o.3, in the f, o. 2, r., á
(hidden beneath sphen. angle.
the squama of
& ſº the frontal. -
(3) Io'718, * -º-º: f, o.4, b. S., near mid- f, o. 2, r., á
dle, hidden under
tempor. Squama.
(4) P & 4 f, o.2, b. S., near -s depression; -
}Il. (hidden e 1. suture in sphen.
f, in each breg- angle; trace on
ma angle. . right.
(5) IIo36, young ff, on both sides - - *-
{} 11157, “ of bregma. -º - *º-
§ 8359, & ſº =º- -º-º: *-
(8) Io272, ad. *- - } -
@ ro257, “.. * - ) *-
Io) Ioo?9, — - left. *º-
Fallow Deer Multiple fissures in - Suture in sphenoidal Fissure, below
IO I young. angle in 2; fissure the upper # of
Fissure in middle
in 2.
Fissure in each
bregmatic angle
1n. I young.
near middle in I;
depression in 5.
the parietal, in
2.

376

From Coronal
From Lambdoid
From Sagittal
From Squamous
Suture.
11ture.
Suture.
Suture.
Arizona Deer.
I 3, adol. sºmºsºms *=º * *
2 I976, ad. cºmmº. *-*. *- *
3) 1972, “” - - emºte *
{{} I966, near ad. mºmº * * *
5) 2, adol. ,- ** * * -º-º:
Arizona Deer smºmº gº * *
(5)
Coassus (Trinidad).
I 375, ad. * *º- *-a -
(2) 146, . * sº <- -
(3) I45, & * *-*. — *
(4) 147, . * * depression, 3 -
(5) 377, * * tº-º-º: -
Coassus Deer - - A depression at the *
(5) end of second
third in I.
Antilocapridae.
Antilocapra amer.
{:} III.33, near ad.
2) IIIoS, ad.
3) III 30, “
(4) IIo99, “
s
f for, smail, r, a
§ III.34, “
6) IIIo.4, “
(7) III oo, near ad.
(8) IIo96, ad.
§::::::.
(Io) III 28, adol.
=
sf, r., o.4, near as-
terion.
American Antelope
Fiss. to foramen in
IO I ,
Suture to foramen
in I;
15oth in the last + of
the parietal.
Antilopidae.
Antilope cervicapra.
(I) I 2049, young
(2) Io'741, adol.
(3) 13913, young
(4) IIo 29, ad.
(5) roos, adol.
depress. to for. b. s.,
(vascular de-
pression).
depress. to for. b. s.,
(vascular de-
pression).
depress. to for. b. s.,
(vascular de-
pression).
depress. to for. b. s.,
(vascular de-
pression).
depress. to for. b. s.,
(vascular de-
pression).
Common Antelope - * A vascular depres- *
(5) sion from a fora-
men under the
squama, on the
last + of the pari-
etal in all. '
Madoqua.
ºr 13543, ad. --- * * --
%2) 13538, . - — sºme *
(3) 1354I, * *º-sº *º- ---
Madoqua, * *ºs mºmºmº --
(3)
377

From Coronal
From Lambdoid
From Sagittal
From Squamous
Suture,
Suture.
Suture.
Suture.
Oryx.
{:} Io'724, ad.
(2) I4r15, “
(3) 13552, “
(4) roo&o, near ad.
sp f, b. S., small, #
f for, o.4, b. S., near
a.Ster.
sp f to a chain, of 3
foramina, r., #
f for, small, b. s.,
Inear aster.
Oryx - *== Spine or a fissure to *
(4) a foramen in all,
in last of the
parietal.
Nylghai.
{:} 5o 24, ad. *-* *E=º * º tº-
2 I66, “ wº-mº * large depression, *
(3) I4095, ad.
vascular, near as-
terion.
large depression,
vascular, near as-
terion.
Nylghai
(3)
In 2 a large, bi-
lateral, vascular
groove near the
asterion.
Boselaphus tragocam.
(I) I 2412, v. young
(2) Iro35, young
§ Trr 68, “
4) III 69, ad.
(5) 13797, “
f, b. s, small, ab.
sphen. angle,
also a f, b. S.,
next to breg-
Iſla.
=
f, b. S. o.3, into mas-
toid angle.
depression, #
depression, #
depression, #
=
Boselaphus trag.
(5)
In I young fissures
above the sphe-li
noidal angle and
near bregma.
In I young fissure
in mastoid angle "
In 3 vascular
grooves in the last
# of the parietal.
Bubalis Swaynei.
3 I3536, young
23 13537, ai.
3) 14443,
mºmºs
Bubalis swaynei
(3)
Bovidae.
{:} Bas grunniens, ado1.
I &
caffer, ad.
–
–
(2)
(1) Bison amer. ad.
2 { % & & & &
& & & £ £ &
3
=
=
4. & & & & & 4
(5) “ “ adol.
Bison 4-º * -º-
(5) *-*.
378

From Coronal .
From Lambdoid
From Sagittal
From Squamous
(3) Camel, Io.271, young
(4) Llama, 14121, ad.
5 & 4 514o, near ad.
(6) “ 6235, young
f, b. S., small.
ff, small, ant. §
Suture. Suture. uture. uture.
Bos indicus. -
(I) v. young f, b. s., in bregma. * f, b. S., in sphen. -
aIngle. angle.
(2) 6403, young f, b. s., in bregma. * - -
angle.
(3) roo&o, “ f, b. s., in bregma. * - -
angle.
(4) 6357, “ f, b. s., in bregma. -º-º: - -
angle.
(5) Iosoo, ad. , - * - -
Indian Bull In 4 young a fis- smº In I young fissure -
(5) sure on each on each side in the
side in the breg- sphenoidal angle.
matic angle.
( 3 Bos taurus, ad. - - -
(2 & 4 & & 4 & - - - -
(2) - -*-> - -
Other Ungulates.
Equidae.
{:} Equus 295, adol. - -*. - -
2 & 4 I4.O., & & - *- - -
{3} Burro, & 4 - * - -
4) Zebra, & 4 - *ms - -
Horses - tº- - -
4.
Camelidae
(1) Camel, 14124, ad. - -e - -
... (2) “ 6368, young | f, b. s., beneath f, b. s., o.8, 3 f, b. S., o.4, § f, b.s., above mas-
the spine. toid angle.
f, b. s., on right.
Camels and Llamas.
(6)
In 2 young a fis-
sure on each
side below the
temporal ridge.
In I young multiple
fissures; in I yo
a fissure at about
the obelion.
In I young a fissure
on each side be-
tween the second
and last thirds of
In 2 young a fis-
sure above the
mastoid angle.
vº,
the parietal.
Suidae. -
(1) S. scrofa, young - - f, b. s., small, in f, b. s., small,
mast. angle. above mastoid
(2) S. :*.
IO739, a
(3) S.
domest.,
2 small f on each
side #
-
angle.
Io 74O, adol.
S. scrofa,
& 6 I4I 26,
I4. I 24,
& 4
§
(6)
Ol.
scrofa, domest.,
387, n.a.d.
& ſº
f, b. S., ab. temp.
T.
f, o.6, r. sphen.
angle.
-
-
-
|Boars and Pigs
(6)
In I adolesc. a
fissure on each
side above the
temporal ridge,
and another in
the right sphe-
noidal angle.
In I adoles. 2 fis-
sures, at the end
of the 2d third of
the border.
In 1 young a fissure
on each side in
the mastoid angle.
In 1 young a fis-
sure on each
side above the
mastoid angle.
379

From Coronal From Sagittal From Squamous | From Lambdoid
Suture. uture. 11ture. Suture.
Ungulata Multiple fissures | Multiple fissures, in: Fissure at middle, Fissureinposter-
(16o) in upper # of the I young camel, 1 in: I Qvis tragel., infer. or mas-
º: ; adol. P1g. I y, fallow deer. toid angle: 2
$on: iº. Fissure at first 3 in Fissure at 3, in: 1 |...Young sheep.
sheep 3 sub g * Ovis tragel. young red deer, Fissure a small
adult' Virginia| Fissure at second # I y. axis, I y. distance above
deer, r" failow (about obelion), camel. mastoid angle:
deer. in 1 young camel. | Fissure at # 9r near || || Y. sº
Fissure in the su- asterion, in: . I I. * 11 -
per.-anterioran- adol. Virginia deer. ºg †el.
gle, in: I young Fissure or suture in 1 young pig. 2
fallow deer sphenoidal angle | Lºs
• 4 s Fissure at th
young Bos indic. in: 2 y. fallow d f : e
º deer. I v. B end of the up-
Fissure near breg- ;as Y " pers of ; OC-
Ima, 111: I young - “. º cipital border
Boselaphus. Fiss. in mastoid an- in: 2 young
Fissure near the gle, in: I y. Vir-| fallow deer.
temporal ridge ginia deer, I y. Fissure Inear
in young Boselaphus, I y | * ºda: I
camels, I adol. pig. young Vir-
pig. Fiss. to à foramen, ginia deer.
- * in: I Ovis stonei
Fºº...], (near aster.), 3
failow deer. ... º.
o celapnt1S , 4
Fissure above the Virginia deer (#,
sphenoidal an- 3, #, #), I Amer.
gle, in: I young antelope (#). 2
###yºung Oryx (near aster.).
*** Suture to a foram.
adolesc. pig. in: I goat (#), |
elk (#), I Dorcel-
aphus (Å), I Amer.
antelope (near as-
ter.).
Spine to a foramen,
in: 2 sheep (#, É),
I elk {}} 6 Dorcel-
aphi (3, #), 2 red
deer (#), 3 Virgin.
deer (2 with a
depression, #, I
with a fissure, #),
2 Oryx (#).
Vascular depres:
sion, in: 8 , Vir- *
ginia deer § I
axis, 5 allow
deer, I Coassus,
5 Antilope cervi-
capra, 2 nylghai,
3 Boselaphi.
38o

From Coronal From Sagittal From Squamous | From Lambdoid
Six Zalophus cali
One - & & 4
One & 4 & &
One & & 4 & young
Two Seals (spec. 2)
2 small fiss. ab.
sphen. angle.
I suture to a for.
above r. sphen.
angle.
I fiss. above 1.
sphen. angle.
large fissure, ab.
the sph. angle.
fissure above the
sphen. angle.
=
=
Suture. Suture. uture. Suture.
Pinnipedia.
Eleven Phoca groenl. -- -ºs -* -
€11 “ foetida - - - - -
.One & & On each side -*. -* -
several fissures
above the
sphenoidal an-
gle, one almost •
dividing the
angle.
Seven & & witulina -º-º: -
Six 4 & & 4 - ** -
Six Walrus * -* - -
Pinnipedia In some seals and * - -
52) Zalophi one or
more fissures
above the sphe-
noidal angle of
the parietal tº
loone.
Rodentia.
Six Castor fiber.
Thirty “ canad.
i
One Fiber zibeth.
One Lepus camp.
One Hystrix 1ucar.
Thirty Sciurus huds.
Twenty Cynomys
Twenty-five Arctomys
Thirty Spermophilus
Twenty Muridae
One Mus, y.
bilatreal fissure,
from squamous
suture, about mid-
dle, towards the
lambdoid suture,
In a few cases a
spine from the
occipital, be-
low the inter-
parietal bone.
up to # the dis-
l tance.
Twenty Neotoma mex. - - - -º
Rodents. --> - In 1 a bilaterall In a few mar'
(185) º
oblique fissure
(young rat).
Imots a spine
from the oc-
cipital into the
parietal bone,
below the in-
terparietal.
381
382 Bulletin American Museum of Natural Aſistory. [Vol. XIX,
IO.
II.
I 2.
I 3.
I4.
I5.
I6.
I 7.
I8.
BIBLIOGRAPHY.
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schädel, etc., Denkschr. d. Kais. Akad. d. Wissensch., Bd.
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BIANCHI, S. S. alcune varietà d. cranio Osservate in feti umani
edin altri mammiferi. Monitore Zoologico, p. 17. Firenze, 1893.
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siol., Vol. XXVII, p. xxi. 1892–1893. -
CORAINI, E. 2 cases in man, 2 in monkeys: Osso parietale
diviso in cranio umanoe studio critico dell' anomalia. Bull. d.
f. Accad. med, di Roma, Vol. XX, pp. 1 21–150. 1893–1894.
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division in adult man; incomplete divisions in children; I
complete and a number of incomplete divisions in apes: Die
tiberzähligen Hautknochen des menschlichen Schädel.dachs;
Abhandl d. K. bayer. Akad. d. Wissensch., II Cl., XX. Bol.,
II Abth., pp. 277–464 (I-190). München, 1899.
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281–295. New York, I 9oo.
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331–332 (figured by Pozzi), 1875.
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1xviii, 1xix; 3d part, pl. x, figs. I and 2.
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AUGIER. Thése inaug., Paris, 1875.
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una frattura, Bollet. Scientif., A. 9, No. 3, 1887.
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thropomorphen; Festschrift z. 7o Geb. Leucharts, 1892, pp. 1–25.
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fontanelle del cranio umano. Rendic. R. Istit. Lombardo, Ser.
II, Vol. XXIX, Milano, 1896, p. 896 et seq.
MAGGI, L. Altri risultati di ricerche morfologiche intorno ad
ossa craniali, cranio-facciali e fontanelle dell' uomo e d'altri
mammiferi. Rendic. R. Istit. Lombardo, Ser. II, Vol. XXX,
Milano 1897, p. I 164 et seq. (See also subsequent volumes of
this publication.) º
MAGGI, L. Fontanelle nello scheletro cefalico di alcuni mammi-
feri. Rendic. R. Istit. Lombardo, Ser. II, Vol. XXIII, Milano
I89o, fasc. Io. (See also subsequent volumes, especially Vol.
XXXI, p. 63I et seq.)
MAGGI, L. Ossicini fontanellari coronali e 1ambdoidei nel cranio
di mammiferi e dell' uomo. Bolletino Scientifico, A. XXI,
Pavia, I899, n. 4, p. 97. (See also N. 3, and the following parts
of this publication.)
MAGGI, L. Note craniologiche. Boll. Scient., A. XVII, N'a 3, 4;
XIX, No. 2 ; A. XXI, N'a 2, 3, 4 ; Pavia, I895, 1897,
I899.
BIANCHI, S. Communicazione sul modo di srilupparsi dell' osso
parietale. Atti d. R. Accad. d. Fisiocritica in Siena, Ser. IV,
Vol. X, 1898.
STAURENGHI, C. Contribuzione alla osteogenesi dell' occipitale
umano e dei mammiferi, con una nota sullo sviluppo del frontale
e del parietale dell' uomo, Pavia, Fratelli Fusi, 1899.
FRAssETTO, F. U. die Entwickelung d. Scheitelbeins d. Men-
schen. Zeitschr. f. Heilkunde, Bd. IV, 1883, pp. 83-86.
FRASSETTO, F. Di II parietali di Primati parzialmente divisi.
Boll. d. Mus. di Zool. ed Amat. c. d. R. Univ. di Torino, 19oo,
n. 376.
FRASSETTO, F. Nuovo caso di parietale diviso in cranio di
scimmia. Riv. di Sc. Biol., 1899, ottobre.
FRASSETTO, F. Di un cranio di Simia Satyrus Linn. con rara
sutura sopranumeraria nel parietale destro. Boll. d. Mus. di
Zool. & Amat. comp. d. R. Univ. di Torino, 1899, Vol. XIV,
No. 344, pp. I-4. Notes on “accessory” fontanels of the
parietal in 371 and Other numbers of same publication.
FRASSETTO, F. Su la probabile presenza di quattro nuclei di ossi-
ficazione nel parietale dell' uomo e delle scimiae. Verhandl. d.
Anat. Gess. a. d. I4 Versamml. in Pavia, Amat. Anzeig., Ergän-
zungsheft z. XVIII Bd. 19oo, pp. 64-78.
TERRY, J. R. Rudimentary Clavicles and other Abnormalities of
Skeleton of a White Woman. f. of Amat. and Phys., Vol.
XXXIII, 1899, p. 413. -
386 Bulletin American M.useum of Natural History. [Völ: XIX.
–
72. TURNER, W. 3d case: Double Left Parietal Bone in a Scottish
Skull. 3. of Anat. and Phys., Vol. XXXV, 1901, p. 496.
73. DUCKworTH, L. H. Proc. A. A. of Gr. Brit. and Ire., p. viii;
%. of Anat, and Phys., Vol. XXXV, 1901. y
74. PARKER, CHAs. A. A Skull Showing an unusual Number of
Wormian Bones Associated with Imperfect Skeletal Develop-
Iment.
(Multiple division of both parietals; case belongs ap-
parently to same category as that of Jung (9).
Proc. Assoc.
Amer. Anatomists, Amer. j. of Anat., Vol. I, 1902, p. 51o.
Alphabetical Index of Authors.
Albinus, 43.
Augier, 46.
Barclay, Smith, 35.
Barkow, 39.
Bianchi S., 31, 64.
Blumenbach, 7.
Boyd, Stanley, 32.
Broca, 38.
Calori, L., 12, 20.
Coraini, E., 33.
Curnow, J., 30.
Debierre, 47.
Deslongchamps, E., I 9.
Doeveren, G., 4.
Dorsey, G. A., 34.
Duckworth, L. H., 73.
Ekmark, C. D., 3.
Frassetto, F., 66, 67, 68, 69, 7'o.
Fusari, R., 28.
Gerdy, 44.
Gorgone, G., II.
Graf, Spee, 51.
Gruber, W., 13, I4, 15, 22, 24, 25.
Hamy, 45.
Hartmann, G., 2I.
Hrdlička, A., 37.
Hyrtl, J., 23, 5o.
Jung, C. G., 9.
Lobstein, F., Io.
Lucae, J. C. G., I6.
Maggi, L., 59, 60, 61, 62, 63.
Mondio, G., 57.
Murray, A., 5.
Otto, A. G., 4o.
Pandolfini and Ragnotti, 58.
Parker, Ch. A., 74.
Pitzorno, M., 54.
Pozzi, 42.
Putnam, F. W., 26.
Rabl–Rüchard, 56.
Ramsey, H. T., 18.
Ranke, J., 36.
Soemmering, Th., 8.
Staurenghi, C., 65.
Sue, 2.
Tarin, I.
Terry, J. R., 71.
Tiedemann, 41.
Toldt, C., 48, 49.
Turner, W., 27, 29, 72.
Voigtel, F. G., 6.
Welcker, H., 17, 55.
Zoja, 52, 53.
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