and enclosing often a large obturator foramen
by coalescing with the ischia. In the Stork,
Ibis, and Flamingo, however, there is no such
union.
In the Scansores, the sacrum of the Parrot
is short and very broad, the ilia and ischia
also short and broad, as well as the ilio-
sacral and sacro-sciatic bones, inclosing a small
foramen ; and the pubes, uniting with the ischia
in two distinct places, encloses a subdivided
obturator foramen. The coccyx of the Tou-
can is long and very flexible.
In the Passeres, the sacrum is composed of
from ten to thirteen pieces ; but in the King-
fisher there is but eight. The coccyx is in seven
to nine pieces, very flexible in the Pies and
Swallow; and in the Woodpecker very strong,
and supporting on its anterior aspect, near the
extremity, a remarkable, round, concave disc,
formed by the coalescence and spreading of
several of the bones anteriorly. Its use is
evidently to support the body by being ap-
plied to the stems of the trees to which it
clings in the pursuit of its prey and attaching
the spreading tail feathers. The ilia, ischia t
and pubes are slender in the Passeres,
and the obturator foramina generally incom-
plete.
The pelvis of the Raptores, or Birds of prey
(fig. 107.), is narrower, the bones more com-
pact and massy, and less expanded than in the
foregoing orders.
The sacrum is narrow, and composed gene-
rally of eleven bones, which, in the Sparrow-
hawk, are ankylosed to the last lumbar ver-
tebra. The coccyx is straight, and in seven or
eight pieces, with a large and blade-like ter-
minal bone directed dorsally (a).
The ilia (6) are proportionally larger, and
project more dorsally than in the other orders,
overlapping the spine with elongated wings,
concave externally ; and a strong tapering ilio-
sacral plate (g), which is directed much down-
wards, as well as backwards, to unite with the
sacro-sciatic plate (e) behind the foramen, so
as to cross the line of the coccygeal bones
almost at a right angle. The ischia (c) are
rather short, strong, and convergent posteriorly,
where they terminate by a long and pointed
spine (i), with a strong but narrow sacro-
sciatic ossification enclosing a small foramen
(/&). The ischio-sacral cotyloid buttresses (/)
are largely developed, The ilio-ischial angle
is remarkable in being reversed or turned for-
ward to a marked extent, 130 in the Eagle,
and 145 in the Owl (see Jigs. 107. and 112.
Fig. 107.
Pelvis of the Eagle, lateral view, showing the reversed
ilio-ischial angle.
11.), a peculiarity to which we have seen,
as before mentioned, a tendency in the peivif*
170
PELVIS.
of the Tiger and some Carnivora, and which
has an evident relation to the increase of
leverage for the muscular power of adduction
required to grasp their prey, as also has
the convergent direction of the ischia just
mentioned. The pubes (d) are long, and are
like the ischia, less directed backwards, form-
ing an ilio-pubic angle of 125 in the Eagle
and 140 in the Owl. They have a great
inward convergence in most Vultures and
Falcons, and in the Hen Harrier and brown
Eagle are closely approximated in the median
line and connected by ligaments in a sort of
short symphysis ; generally the ischia and
pubes unite posteriorly to enclose a small
obturator foramen in the Diurnal birds of
prey. In some Falcons and Vultures, how-
ever, according to Carus, they are united in
their whole extent ; while, in the Owls, this
union does not take place at all.
The Reptile pelves present some specimens
which approach the Mammalian type, in the
formation of a perfect pelvic girdle by inter-
pubic and inter-ischial symphysis. In these
animals, however, the three components of
the innominate bones remain separate through-
out life, and are connected in the acetabula
by ligament only. The manner of articula-
tion of the ilia with the sacrum is also cha-
racteristic. We have seen that in Mammals
this connection of the ilia takes place about
the centre or at the anterior half; and in
Birds by the whole length of the alae. In
"Reptiles it takes place by the tip only of the
upper extremity of the ilia, giving much less
strength, but far greater mobility to these
bones. In the Chelonian and Saurian reptiles
also, the ilia are directed forwards and down-
wards instead of backwards and downwards, as
in Birds and Mammals, and thus the axis of
the anterior pelvic outlet is directed upwards
and forwards, and the lumbar vertebras, instead
of the coccygeal, form part of the posterior
pelvic wall. The pelvic bones are simple,
and the sacro-sciatic notch can hardly be said
to exist.
In the Ophidians and some Saurians the
pelvis, like the corresponding extremities, is
totally wanting.
In the Chelonia, the fresh-water, and the mud
Tortoise, or Trionyx, have a sacrum composed
of three pieces, soldered, like the dorsal ver-
tebrae, to the back-plate. Their long transverse
processes project from it, and unite in a tuber.-
cle at their apices, to which the ilia are attached.
The caudal vertebras are numerous.
The ilia(fis>. 108. a.} are short, thick, curved
roundish and clubbed inferiorly, and are di-
rected outwards, forwards, and downwards,
extending under the back plate directly be-
tween the sacrum (at i) and the acetabula. In
the Tortoise and Trionyx they are moveable
upon the sacrum forwards and backwards.
From the acetabula, the ischia (c), larger than
the ilia, pass, almost at a right angle, backwards
and inwards, and unite in a median symphysis
(rf), forming the real pelvic circle, and present-
ing a sharp angle posteriorly in the Trionyx
(/) and fresh-water Turtle. In the land and
fresh- water Tortoise this symphysis is continu-
ous anteriorly with the inter-pubic (e), forming
with it a cross-shaped suture, and the ob-
turator foramen on each side is distinct and
separate ; but, in the Turtle and Trionyx, as in
most reptiles, the inter-pubic and inter- ischi-
atic symphyses are separated and connected
by cartilage only, and thus, in the dry bones,
the obturator foramina are coalesced in one
large opening, and the pubes and ischia have
the appearance of large ribs connected at their
ventral extremities. The pubes (A) are the
Fig. 108.
9 f
Pelvis of the Trionyx, or Mud Tortoise, superior
view.
largest of the bones in the reptile pelvis, and,
as seen in the Turtle, pass each from the
acetabula as a thick bone, which expands as
it passes downwards into a broad plate, and
divides into an inner portion which unites
with its opposite fellow in a symphysis (e, e'}
and an outer portion, free and directed ex-
ternally (h). In the Chelydes all the pelvic
bones are ankylosed to the plastrum or to the
back-plate ; but in the others, the ischia and
pubes are connected to the plastrum by liga-
ments only. The anterior pelvic opening in
the Chelonia is directed upwards and forwards.
The pelvis of the fossil Plesiosaurus is very
like that of the Tortoise, with narrow, small,
and weak ilia, with the fan-like, spreading
ischia, and large square pubes uniting in
a common symphysis, by a crucial suture.
The pelvic and shoulder bones have a great
resemblance in the Chelonian as well as in
the Saurian reptiles.
Of the Saurian reptiles the Crocodiles have
two sacral vertebras with large spines (Jig. 109.
a, a'), which support the ilia by strong prismatic
apophyses, ankylosed together at the ends, and
separated by a suture, in the young animals,
from the bodies of their vertebras. The caudal
bones in all the Saurians, are very numerous.
The ilia (b) are very short, and in some
species almost cuboid', slightly bent, with an
inward concavity, and directed downwards
and a little forwards, but almost at right
angles to the spine, with the superior angle
(e) projecting backwards. The ischia (c)
are long, and directed, like the sides of an
PELVIS.
171
isosceles triangle, downwards and inwards,
uniting in a median symphysis (/), and much
resemble the coracoid bones of the shoulder.
The acetabula of the crocodile look di-
rectly outwards, have strong inter-articular
ligaments, and are formed only by the ilia
and ischia, the latter presenting, just below
the acetabulum, anterior apophyses which
support the pubes. The pubes (d) are directed
much forwards, downwards, and towards each
other, but do not touch in the median line,
being united only by the abdominal aponeu-
Fig. 109.
n
Pelvis of the Gangetic Crocodile (side view).
rosis (A). They are connected by the anterior
border with the posterior abdominal ribs (g).
The Lizards have, like the crocodiles, two
sacral bones, as in the Iguana and Great
Monitor. In many Lizards the sacral trans-
verse processes (fig. 110. A, a) are very
long, and, being articulated by suture to
the bodies of the vertebrae, appear, at first
sight, like additional ilia. This is particularly
the case in a fossil specimen recently dis-
covered by Sir Charles Lyell.* The ilia (b) are
directed forwards and downwards, and the su-
perior extremity projects backwards in a trun-
cated point (<?)' The ischia (c) are larger, and
directed backwards at a great angle with the
ilia, uniting in a truncated median symphysis,
which is separated from that of the pubes ;
so that the obturator foramina are divided
only by ligament (g), and communicate in the
dry bones. In some Lizards the ischia present
posteriorly a spinous projection. The pubes
participate, with the ilia and ischia, in the for-
mation of the acetabula, present a spine at
their cotyloid extremity (d), curving down-
wards and outwards, and unite in a very
narrow symphysis ; but in the Monitors and
Sauve-gardes the pubic symphysis is distin-
guished by its greater breadth and truncated
form (/). The ilio-pubic angle is about 160,
retiring posteriorly in the Great Monitor
Lizard, and the ilio-ischial ansile is very acute,
being 60 only (see Jig. 112. fs.).
In the Menepoma alleghani the sacral trans-
verse processes are directed backwards, and
support apophyses to which the ilia are at-
* Lecture at the Royal Institution.
tached. The pubes and ischia are short and
oblong, and so approximated as to leave no
obturator opening.
Upon the pubic spine, in the Cameleon, are
two cartilages, which have been stated by
Duges to be of a marsupial character.
A Fig. 110.
A, jjelvis of the Great Monitor Lizard.
B, ilium, ischio-pubis, and marsupial cartilage of the
Salamander (after Duges), seen from below, and
twice the natural size.
From the pelvis of the fossil Pterodactyle
Cuvier concludes that the forward direction
of the ilia, the anterior position and pointed
extremity of the pubis, and the separation of
the pubic and ischiatic symphysis, ally this
animal to the Saurian reptiles.
In the tailed Batradiia and Ichthycic rep-
tiles there is but one sacral vertebra supporting
rib-like transverse apophyses which connects
them to the ilia. The ilia are long and slender,
and the pubes and ischia are blended together
in one large, squarish, cartilaginous plate, not
perforated, and loosely connected by ligament
with the one of the opposite side.
In the Proteus the ilia are small, and the
whole pelvis very little ossified. In the
Salamander, also, the ilia are small (see fig. 1 10.
B, a). A cartilage, of a Y shape (d], is placed at
the anterior margin of the ischio-pubic plate
(6), which Duges looked upon as marsupial,
but which Meckel has considered as part of the
sternal elements, and which is a bifurcated pro-
longation of the cartilaginous ischio-pubic sym-
physis (c). There is also a very small obtu-
rator opening in the ischio-pubic plate ().
The ossification of the pelvic bones in these
animals, according to Duges, takes place in the
same order as in man. The pelvis of theAxolotl
is, like that of the Salamander, not quite ossi-
fied. In the Siren, according to Cuvier, there
is no vestige of a pelvis. In the Ophisaurus,
C(Scili(E, and Amphisbcena, there are only rudi-
mentary vestiges of the ilia and ischia ; and in
the apodal Saurians, as in the Ojihidia, a single
bone only is found, under the skin near the
anus. In Pseudopus anguis and Acontia are
simple elongated pelvic bones, articulated by
ligament to the last dorsal transverse processes.
In Eryx boa a pair of elongated bones lie
parallel to the rectum, free from the spinal
column. They are sometimes found in several
distinct pieces.
In the Sauroid reptiles the acetabula are di-
rected horizontally outwards, and the inflex-
ions of the feet are made perpendicularly to
the rachis or plane of motion, the thigh being
172
PELVIS.
directed outwards, the knee always bent, and
the body trailing. They walk on the fore and
hinder legs alternately, and leap by a sudden
flexion of the body.
The pelvis of the Anourous Batrachia is
interesting from the changes which affect it,
in their transition from the ichthycic to the
quadrupedal condition.
The sacrum of the Frog (Jig. 1 1 1 . A and B)
is considered by Duges to be formed by
the last dorsal vertebra, which closely re-
sembles the preceding ones, except in having
very long and strong transverse processes (e),
to the tips of which the ilia are moveably arti-
culated. In the Rana pipa and Toad, how-
ever, the sacrum presents evident indications
of a "division into two vertebrae, there being
on each side a foramen for nerves, with two
prismatic and very rough transverse pro-
cesses. The coccyx of the Frog is composed
of two pieces (/), which, in the adult state, are
ankylosed together and to the sacrum, and
considered by some to form part of that bone.
They are formed, respectively, from three
points of ossification. In addition to these
there is a long cylindrical terminal spinous or
btyloid process (g), which is formed by a single
separate ossific point, and becomes ankylosed
so the other part at the adult period. This is
tonsidered by some to be a second sacrum,
end by others a coccyx. It has been supposed
ay Duges to cause, by its progressive ossific
development, the mortification and dropping
off of the tail at the period of transition from
the tadpole condition, and thus closing up
the spinal canal posteriorly.
Fig. 111.
A, anterior view of the Frog's pelvis ; B, side view
of the same bones; c, pelvic bones and fins of
Trout.
The ilia (b) are very long and cylindrical, and
directed back wards,becoming almost horizontal
in the Rana pipa. They suspend between them,
by their apices, the long transverse processes
and body of the sacrum, like the springs of a
coach. At their opposite extremities tney are
ankylosed, not only with the ischia and pubes,
but with each other (If) ; and thus the acetabula,
of which they form the greatest portion, are
closely approximated, and the pelvic outlet
assumes a V shape with the base at the
sacrum and the angle at the coalesced ex-
tremities of the ilia. The pubes and ischia
of both sides are coalesced together in an
azygos osseous plate ;(c), with a central
rounded crest marking the position of the
symphysis (d), the pubes being the last to
ossify. There is no foramen obturatorium.
The posterior outlet of the Frog's pelvis looks
almost directly upwards, and the anus opens,
at the extremity of the coccygeal spine, upon
the dorsal aspect of the animal.
In the immature Batrachian a triangular-
shaped cartilage intervenes between the op-
posing ilia and the other pelvic bones in the
acetabula, which afterwards becomes oblite-
rated by the ankylosis of the bones. Duges
calls it an " os paracotyleal," analogous to the
" paraglenal" bone of the shoulder of the same
animal. There are also epiphysial pieces on
the ilia and ischia which represent the crest and
tuberosity of those bones respectively.
The solidity and firmness of union of the
ischio-pubic portion of the pelvis in the frog
is a remarkable instance of modification and
adaptation of form to meet the requirements for
a strong and firm hold for the powerful triceps
cruris, external obturator, hamstring, and ad-
ductor muscles in the thigh of this animal.
The single pair of glutei also obtain an ex-
tensive attachment from the long ilia, and the
pyri/brmes from the long coccygeal spine, while
the strong abdominal muscles, acting on the
moveable ilia, give, as it were, an additional
segment to the hinder extremities. In this
manner the frog's pelvis is strikingly and di-
rectly adapted to its leaping progression.
In the Fishes the pelvic structures dwindle
to elementary pieces, such as we have, men-
tioned in the bimanal and apodal Reptiles,
and finally disappear altogether.
The pelvis is represented in these animals
by two bones, sometimes coalesced into an
azygos bone, which support the ventral fins.
In the Pisces thoracici these are suspended
by ligament to the coracoids, by which they
are advanced anterior to the pectoral fins,
and connected to the head ; but in the
Pisces abdominals they are detached from
the coracoids, and are suspended in the
muscles at the posterior part of the ab-
domen. t They are, however, subject to
great diversity of position.
Owen considers the pelvic bones of fishes
to be the homologues of the pubes ; but, in the
opinion of Carus, they are to be considered as
ilia. Their inferior and ventral position, their
occasional union in a symphysis, their frequent
coalescence, and their attachment to the
generative organs, however, would support
rather the conclusion of Professor Owen ; the
support of the bones of the extremities not
being exclusively the iliac attribute, but also
PELVIS.
173
usually contributed to by the pubes andischia.
In Fishes, a supporting arch from the spinal
column to the posterior limbs * is not wanted,
but rather a free and unimpeded motion for
the caudal extremity, used in propelling the
body.
In the Angler there are two pelvic bones,
each consisting of a vertical portion, which, in
this instance, seems to represent the ilium, and
a horizontal one, which meets in a symphysis
with the one on the opposite side, and is the
homologue of the pubis, the pectoral rays
being attached to the angle of union of the
two portions. In the Rays and Sharks,
where the pelvic extremities are better de-
veloped than in other fishes, the pelvic bones
consist of one piece, placed transversely,
resembling that which supports the pectoral
fins, and suspended loosely, like it, by a
ligament to the spine. In the Sharks and
Chimeras are found, articulated to it, by means
of an intermediate cartilage, two club-shaped
bones, called claspcrs, which are used to em-
brace the female in the generative act. In
the Torpedo, and also in the Cyclobates oligo-
dactylns, an extinct Ray, the pubic bone sends
forward two processes, somewhat resembling
marsupial bones. In the Sturgeon, the pelvic
bones are almost entirely separated from each
other, and consist of small triangular pieces,
with their apices directed forwards, and sup-
porting the cartilaginous fin rays. In the
Cod-fish there are two sub-triangular bifur-
cated bones, connected to each other by liga-
ment, and suspended from the coracoids, the
rays of the ventral fins springing directly from
them. In the Trout, the pelvic bones are also
two in number, flat and of an elongated tri-
angular shape, with the base directed pos-
teriorly, and supporting the ventral fins (see
fig. 1 1 1. c). In the Haddock, there is a single
bone, presenting a central oval opening with
the snorter diameter transverse. In the
Cyprinus, Scomber, and Zeus, they present
backward spinous projections. In the Rhombus
and Loncaria there is seen an ankylosis of
the anterior caudal vertebrae, forming a sort of
sacrum, and presenting the first indication of
the formation of this bone in the animal
kingdom.
Subjoined is a table, showing the compara-
tive pelvic angles in Man and the principal
genera of Mammalia, Birds, and Reptiles. The
measurements were principally taken, with
great care to insure correctness, from the
specimens in the Hunterian Museum, through
the kindness of Professor Owen. The rela-
tive size or total disappearance of the verte-
bro-iliac, sacro-vertebral, and the ilio-pubic
and ilio-ischial angles in the different tribes,
will be here seen at one view. It may be
observed that the two former may vary some-
what through inaccuracies in articulating the
skeleton, or with the variations of the ver-
tebral curve, and that the results here given
are to be taken in this particular, as approxi-
mative only. But the ilio-pubic and ischial
angles cannot, from the ossific union of the
bones, be subject to such accidental variations.
The accompanying diagram is intended to
show the absolute lines of direction or axes
of the pelvic bones and spine seen in profile,
with the angles above referred to, in the prin-
cipal pelvic types.
Fig. 112.
Lines of direction and profile angles of the pehic lones. 1. Human type; fac, vertebro-iliac angle; fag,
sacro-vertebral angle; acd, ilio-ischial angle ; acb, ilio-pubic line, forming an angle in all other animals.
2. Orang type. 3. Monkey type, no ilio-ischial angle. 4. Edentata type, ilio-pubic angle reversed. 5.
Carnivora type> ilio-ischial angle reversed. 6. Pachyderm type. 7-. Ruminant type. 8. Rodent type,
no ilio-ischial angle. 9. Kangaroo type. 10. Bird type, no "ilio-ischial angle. 11. Raptores type, ilio-
ischial angle reversed. 12. Chelonian type. 13. Saurian type, ilio-pubic angle reversed, and remarkably
acute ilio-ischial angle.
174-
PELVIS.
TABLE OF COMPARATIVE PELVIC ANGLES.
{!
Is
Sj
Sacro-
vcrtebral.
1. Man ...
Decree,
Degrees.
Degrees.
110
Deg.
117
2. Orang ...
160
125
165
150
3. Chimpanzee -
155
120
do.
160
4. Gibbon -
do.
130
170
5. Baboon (brown)
do.
110
155
(160
90)
6. Monkeys -
to
to
[170
120)
7. Lemur (albifrons) -
170
120
8. Loris gracilis -
do.
75
9. Sloth (Ai) -
145
155
135
10. Mylodon (fossil)
125
155
120
160
eversed
11. Megatherium (ditto)
do.
125
eversed
12. Armadillo
155
150
145
13. Ant-eaters
140
155
do.
eversed
14. Lion
150
120
170
15. Tiger
160
110
165
do.
eversed
6. Leopard -
150
120
do.
7. Hyaena -
140
125
160
8. Bear (brown) -
do.
do.
do.
9. Badger -
do.
130
170
20. Racoon -
150
145
160
21. Elephant
120
100
145
170
22. Rhinoceros
125
150
do.
do.
23. Hippopotamus
IfiO
125
170
160
'24. Hog ...
145
120
do.
do.
25. Tapir ...
125
145
140
26. Horse ...
130
130
145
27. Ox tribe -
(145 i
I to }
130
130
150
(150)
28. Deer tribe
150
140
150
160
29. Irish deer (fossil) -
145
135
do.
do.
30. Giraffe - - -
150
140
145
170
31. Camel ...
140
120
155
155
32. Sheep and goats
33. Rats and mice
145
170
130
150
150
170
34- Hare
165
120
160
35. Jerboa ...
140
145
36. Kangaroo
do.
135
170
37. Wombat -
160
130
do.
38. Thylacinus (cyno-
ceph)
150
115
do.
39. Ornithorhyncus
140
120
155
tO. Echidna (hystrix) -
do.
110
41. Hedgehog
130
150
42. Bat (Ternate)
100
(150
155)
43. Birds, generally
\ to
(160
to [
160)
44. Ostrich ...
160
155
45. Uhea -
do.
140
46. Cassowary
do.
155
47. Apteryx -
155
140
140
reversed
48. Eagle ...
150
195
130
reverset
49. Owl - - -
do.
140
14.7
reversed
( 80
50. Chelonian reptiles -
1 to
130
80
(100
( 60
51. Crocodiles
] to
140
130
( 90
52. Lizards (Monitor) -
( 40
\ to
( 90 j
160
reversed
60
Having thus taken a general review of the
progressive development of the pelvis, and
traced it from its most perfect form in man
to its most rudimentary elements in the fishes;
we can enter more prepared into the consi-
deration of the serial homologics of the pelvis
and its ligaments.
SERIAL HOMOLOGIES OF THE PELVIC BONES
AND LIGAMENTS.
The sacrum, according to Professor Owen,
is to be considered as the centrum of the pelvic