THE FEMALE REPRODUCTIVE ORGANS
The mechanism and organs of reproduction differ so widely in the classes
under discussion that it will be necessary to describe separately the
alterations in mammals and in birds. Examples of abnormality and disease
are not very numerous and I shall cite cases for many of the conditions
rather than prepare comparative lists as has been possible in many
foregoing sections. Some years ago Dr. Edward A. Schumann[40] studied
the comparative anatomy and physiology of the mammalian female
generative organs, and I shall condense and paraphrase his work. (The
complete articles may be found as in the references below.) This
gentleman, because of his gynecological experience and broad interest in
comparative biology, has been consulted whenever unusual material from
this tract has presented itself so that many of the descriptions that I
shall employ are due to him. I take this opportunity to acknowledge with
thanks his interest and helpfulness.
COMPARATIVE ANATOMY IN EXPLANATION OF HUMAN UTERINE ANOMALIES.
The development of the genital tract seems to be essentially the same
through all orders in that the genital ridge forms the ovary and its
attachments while the Mullerian ducts supply the tubes, uterus and
vagina. Early in fetal life these two longitudinal ducts begin to
approach one another, and by the end of the third month should be in the
position which they are to retain for the full development of their end
result. In the human being this position is complete union and fusion,
with the production of a single tube from the uterine fundus to the
exterior, while in the lowest mammals, edentates and marsupials, the two
Mullerian ducts retain their lateral position, and upon completion of
embryonal life a double tube from the ovaries to the exterior is found.
If the normal fusion of the ducts does not take place, and if for any
reason their proper relation is not reached, an abnormality will result
varying according to the stage of development that has been reached.
Thus in man instead of a single uterus of triangular shape and a single
cervix, a double set of tubes may be found. It can be shown that the
abnormalities of the human uterus are of definite and fixed types
corresponding to an arrest of fusion or completion of the developmental
cycle as given for the Mullerian ducts and further that these very
deformities are comparable to normal organs of lower orders. In other
words abnormalities in arrest of development in the human uterus
represent normal types of lower uteri at various evolutionary stages. In
monotremes there are two ovaries, tubes, uteri, cervices, a urogenital
passage and a clitoris. This corresponds with Uterus didelphys with a
single vagina. This abnormality while occurring in the lowest mammal,
does not represent the most marked deformity known for the human being—
that in which the double tube remains to the vaginal outlet, a condition
found in the marsupials. In this order the uteri are entirely separate,
and each is fitted with its own vagina. The next higher order, Edentata,
seems somewhat out of place if it be judged by its female genitalia
since it is possessed of a triangular uterus and single vagina but
without distinct cervical segment; the tract is very similar to that of
the Primates.
Rodents, in the various families, present no uniform uterine
construction, there being four kinds corresponding to as many degrees of
Mullerian duct fusion and differentiation. The lowest forms simulate the
marsupials, another group is like the monotremes, a third shows a
complete fusion with a single cordiform uterine body, while the last
resembles somewhat the first, but the uterine divisions are bound
together and the vagina is divided only half way down. The Insectivora
occupy a transitional position resembling higher and lower groups in
having a long uterovaginal canal, without distinct cervix, extending
upward into long curved cornua. Cetacea (whales) have a highly rugous
single vagina, a distinct, short uterine segment divided into two
separate horns. The genitalia of Sirenia resemble those of the last
group, but the cervix is better developed. In the last three orders the
clitoris begins to be well developed and to present externally.
Proboscidea have a single vagina separated from the short uterine body
by three transverse folds corresponding to the cervix; the two cornua
are long and wide.
“The foregoing orders present in their uteri all the essential
characteristics of uterus bicornis unicollis with single vagina and are
therefore the homologues of this anomaly in man.”
In the Perissodactyla, the bicornate uterus has a body of a little less
than half the whole length; there is a sphincter at the lower end of the
body but no projecting cervix. The cornua are longer still in the
Artiodactyla and are coiled in a manner suggesting spiral sheep’s horns;
there is a differentiated projecting cervix. In cats the length of the
uterine body and of the cornua are almost equal and both are flat tubes;
the cervix is prominent and the vagina long and rather smooth. The dog’s
uterus is similar but the two cornua are bound together or fused before
the point at which their termini enter that of the uterine body; the
cervix is not very prominent, but well formed and the vagina is rugous.
These types correspond to the uterus cordiformis. Lemurs have a common
uterovaginal cavity like the Edentata. The lower monkeys possess a long
slender uterus with definite superior lateral angles, the last vestiges
of the cornua, a prominent cervix and a short rugous vagina. The higher
apes have a uterine construction almost identical with that of man at
the stage of infantile development.
“From the foregoing study it is clearly shown that every anomaly of the
female genitalia in Man is in reality the result of atavism and hence, a
degenerative change, and inasmuch as every special form of anomaly finds
its counterpart in the normal anatomical arrangement of the analogous
structures in one or another of the great mammalian groups, one
additional item of proof is offered in support of that greatest of
biological doctrines, the descent of Man from the lower forms of life.”
ANATOMY OF LABOR.
In a second article Schumann reviews the comparative anatomy of labor,
demonstrating that the basic principles are essentially the same,
alterations only being in the direction of accommodation to the pelvic
construction. In order to make the analysis comparable with human
conditions the pelvis is studied as if the animal were standing erect
upon the hind limbs.
The salient points of difference between the quadruped pelvis and the
biped, human type may be epitomized as follows: (a) The entire pelvis
lies (with the animal in its normal station) in a generally horizontal
position with a slight slope downward anteriorly. (b) The false pelvis
is almost entirely wanting, there being practically no bony structures
above the brim with the exception of the small upper portions of the
ilia. (c) The pelvis in quadrupeds is never basin-shaped, the lateral
walls from the iliac crests to the tuberosities of the ischia lying
roughly parallel to each other and enclosing a pelvic cavity rectangular
in outline. Only in the highest apes does the basin-shaped pelvis
appear. (d) The angle of the axis from the promontory of the sacrum to
the symphysis is always greater in the quadrupeds than in man, averaging
in the former from 70 to 80 degrees, in the latter about 55 degrees, (e)
The symphysis pubis is an extremely long joint, being frequently greater
than half the length of the entire pelvis, (f) The sacroiliac joint is
more or less movable in all quadrupeds, especially in young animals. The
rotation of the sacrum on the ilia increases the anteroposterior
(dorsoventral) diameter of the outlet and at the same time wedges apart
the ilia, thus increasing the lateral diameter.
In regard to the forces of labor it is to be pointed out that in the
lower mammals the pregnant uterus hangs below the pubic arch so that the
fetus must rise at an angle of about 45 degrees to pass over the pelvic
brim. In so doing it meets the narrowest part of the triangular bony
pelvic inlet, the anterior pubic angle. Since the sacrum is above and
out of the way, the lateral diameter is the one which must be suitable
to the passage of the presenting part. This is the head in homo, the
largest part of the fetus, but in lower animals either head or breech
often accompanied by one or more extremities, may present; the head is
not the largest part in lower mammalian fetuses. The uterine contraction
proceeds as in man, the fundus and cornua acting alone until the cervix
contains the fetus, at which time all parts contract. In the bicornate
organ both sides must contract or the fetus might be forced from the
gravid to the empty side. In multiparous animals with both uterine horns
occupied, the fetuses lie head to head, breech to breech and are
expelled alternately from each side.
In uniparous animals rotation is in the nature of an accommodation of
the greatest diameter of the fetal body in cross section to greater axis
of the mother—the dorsoventral. Uterine contractions cause the fetus to
unfold from its elliptical form and to assume an extended position,
permitting head or breech to enter the lower pelvis. The pubic angle
having been passed and the extension of the presenting part being
successfully accomplished, there is no striking difference in the manner
of external expulsion of the fetus.
DYSTOCIA.
Dystocia in domesticated animals is a well studied subject, and its
general clinical phases are fairly well known. Several cases have been
observed, details of which are worthy of note since some of them are
entirely complete.
Inertia uteri as a single non-obstructive condition seems not to have
been observed here, although well enough known to veterinarians. Nor has
a case of dystocia been seen as the result of excessive expulsive force.
Obstruction to natural passage by bony deformities or malformations is a
common occurrence in man but not so in lower animals. There may also be
dystocia by reason of a normally formed but too small pelvis when the
female has been impregnated by a much larger male, or if the female
conceived before the pelvis has achieved its full growth.
Deformities may be due to irregularities of bony development, exostoses,
fracture or diseases of the osseous system. A most interesting case of
this type occurred in a Barbary ape (_Macacus innuus_) which had been in
the collection for two years and was apparently in good health when
discovered in labor.
No progress being made and the animal becoming shocked, an ineffectual
attempt was made to deliver by version, the monkey dying during the
operation. Upon autopsy the uterus contained a fetus apparently at
term. The head was extended so that the face presented, but the head
was not engaged. The cervix was fully dilated but the uterine muscle
was relaxed and flaccid. The fetus was dead when the animal was first
examined. The uterus contained two placentæ as is normal for these
apes, the left placenta being the place of attachment of the fetus
while the right one was somewhat smaller and presented no umbilical
cord. The fetus was normal in size and form, the face was extended and
its lower portion far advanced in a caput succedaneum. The
measurements of the fetal were as follows: bitemporal 5.5 cm.,
biparietal 6 cm., occipitomental 8.5 cm., occipitofrontal 7.5 cm. The
pelvis (dried specimen) presents a most interesting condition. The
sacrum is bent sharply forward, carrying with it the border of the
ilia, which are bent upon themselves forward and downward. The lateral
walls of the pelvis are greatly narrowed, the ischia drawn inward. The
pubes and the symphysis are fairly normal. The pelvic measurements
are: diagonal conjugate 6 cm., true conjugate 4 cm., greatest
transverse 4 cm.
It is apparent at a glance that here was an impossible labor, since the
head of the fetus could not possibly enter the pelvis, the size of
which, _intra vitam_, must have been less than the above measurements by
reason of the soft parts. “This is in the experience of the writer a
unique case of a complete obstetric history, plus the specimens, of
labor with an osteomalacic pelvis in a wild animal.”
Another case may be added to those already reported by Dr. Schumann, as
follows:
Hairy rumped Agouti (_Dasyprocta prymnolopha_). Dystocia. An
apparently normal fetus occupies the left uterine horn. The nose was
engaged in the pelvis and has been moulded in a curve pointing to the
right. The fetus measures—bitemporal 30 mm., cervical-coronal 31 mm.,
length of fetus 17 cm. Pelvic inlet in the fresh state measures 18 mm.
transversely and about 17 mm. anteroposteriorly. The umbilical cord is
10 cm. long and appears normal as do the membranes. Placenta presents
as a spherical mass of hard dense consistency, 35 mm. in diameter and
with apparently normal placental tissue occupying the lower border of
this spherical mass. On section the mass shows areas of alternating
soft red tissue separated by communicating trabeculæ of dense white
fibroid tissue. This mass is distinctly encapsulated, but the nature
of the enclosing membrane is indeterminate. The pelvis in dry state
shows evidences of malformation due to trauma. The right ileum is
pushed forward and inward carrying the acetabulum a short distance
inward and backward. There is a marked thickening about the right
acetabulum. At the upper portion of the symphysis there is marked
bending backward toward the sacrum with thickening of the bone. The
last sacral vertebra is sharply bent and anchylosed, forming an angle
of sixty degrees. The pelvic measurements in the dry state—at superior
strait-transverse 24 mm., right oblique 23 mm., left oblique 26 mm.,
true conjugate 22 mm., outlet 17 mm., between the ischiatic spines.
This is obviously a traumatic malformation and forms a relatively
contracted pelvis. The delivery of an adult fetus is impossible.
Cape Hyrax (_Hyrax capensis_). Impossible labor due to malformation of
the pelvis. This animal died as the result of shock and exhaustion of
labor. She was pregnant of two fetuses, one of which was extracted
manually by the keeper but was dead at birth. Twenty-four hours later
the animal was found dead. On autopsy there was present a fully
developed fetus in the right cornu, the head just above the pelvic
inlet. The left cornu was large and boggy. The myometrium of the right
side was so thin as to be almost transparent. On examining the bony
pelvis the reason for the dystocia is at once apparent. The sacrum is
tilted to the right, and the body of the left ileum is bent sharply to
the right, the pelvic inlet being obliquely contracted, the right
oblique diameter being 16 mm. while the left is 23 mm.
The pelvic obliquity made the birth of a full sized fetus impossible,
the one delivered being under developed. The myometrium was evidently
stretched almost to the point of rupture when death occurred.
Obstruction to the birth canal by abnormalities in the soft parts, such
as muscular rigidity, edema, or inflammation, tumors, atresia or
developmental defects are occasionally seen by veterinarians but have
not been encountered here.
Dystocia from uterine displacements are uncommon except such as may
depend upon the failure of support by the abdominal wall, since this is
the principal support of the organ especially when gravid. Hernia or
hysterocele is known and anteflexion has been seen. Torsion, a rare
human condition, is not uncommon in lower animals probably due to the
loose dependent position of the pregnant cornua, attached only to the
pelvic walls by slender inactive suspensory ligaments. A case may be
reported, not originally described.
Canada Porcupine (_Erethizon dorsatus dorsatus_). Obstructed labor.
This animal died from exhaustion due to an impossible labor. On
autopsy the abdomen contained a moderate amount of clear serous fluid
with one small blood clot. The right uterine cornu was distended with
a fetus to about the same diameter as the uterine body. This cornu was
congested and edematous and its walls very thin. The cornu was twisted
one-half full turn from right to left, so that the pregnant portion
overlaid the uterine body anteriorly. The torsion produced a
compression of the vessels on the right side to the point of violent
congestion of the cornu. There was no apparent rupture of the uterine
walls, death having occurred from exhaustion. The fetus and its
membranes were normal.
Many forms of abnormalities in position are recognized for domesticated
animals, but since we know so little of the early stage in the wild
specimens no data can be given.
Complicated labor in lower varieties of animals will follow lines
similar to those for man and domesticated animals. Hemorrhage from
trauma is not common at term, but several cases of abortion following
injury have been seen. Postpartum hemorrhage might be expected in the
higher apes which have a large discoid placenta similar to the human
form, but when the placenta is more loosely attached and is subdivided
as in lower forms, such bleeding is of no danger; when a cotyledon is
torn from the ungulate uterine wall, a free hemorrhage sometimes occurs.
Geoffroy’s Marmoset (_Leontocebus geoffroyi_). Puerperal relaxation of
the uterus with fatal hemorrhage. The uterus is 4 cm. long, 15 mm.
wide at intertubal line. Uterine wall averages 2 mm. in thickness.
Peritoneal surface is smooth, glistening and intact. Uterine
musculature is soft and relaxed. Entire organ is intensely congested
and on section uterine cavity contains a large firm blood clot
completely filling it. Mucosa is of deep purple color, shows many
fragments of decidua and is the seat of profuse hemorrhage.
Placenta previa is very rare. A row of cotyledons may form near the
internal os, therefore like a placenta previa, but it appears to be of
no consequence. Premature separation of the placenta is known to
veterinarians, and is exemplified by the following case in our records:
Black Lemur (_Lemur macaco_) was found dead in its cage. Upon autopsy
the uterus contained a small fetus with one leg and the tail
protruding from the vulva. The fetus was normal in size. There was a
large amount of free blood in the uterine cavity and extensive
extravasation into the myometrium. The placenta was completely
detached.
Rupture of the uterus and cervix have not been seen, but a traumatism of
the vagina gave occasion for the following death:
Bactrian Camel (_Camelus bactrianus_) died of shock in labor. Upon
autopsy the animal was found to have hydatid disease of the liver,
lungs, and spleen, cirrhosis of the liver, and nephrolithiasis.
Protruding from the vulva was a portion of the fetal membranes, the
whole vaginal wall and several coils of intestine which had escaped
through a large rent in the posterior vaginal wall. The anterior wall
was swollen and edematous, the whole region surrounded by clotted
blood. The cervix was obliterated, the membranes unruptured, the fetus
in the normal extended head presentation. The veil-like placenta was
somewhat injected but otherwise normal. There was some hemorrhage
about the rectum but none in the free peritoneum.
This animal had broken her hind leg just above the fetlock three weeks
before falling into labor, and was unable to stand. It is evident that
the difficulty of delivery associated with an unnatural and forced
posture due to the fractured leg was sufficient cause for the rupture of
the vagina where the tissues were degenerated as a result of the
coincident general disease.
Inversion of the uterus is one of the common accidents of labor among
all animals, most frequently seen in ruminants. It is a condition more
to be expected in lower animals than in man because of the long slender
relaxed suspensory ligaments, the length of the uterus and the rigor of
the contractions. The immediate causes are those operative for human
beings. Three cases are recorded—one in an axis deer, one in an opossum,
one in a mouse, the last being detailed in the following notes:
A Japanese Waltzing Mouse (_Mus wagnerii rotans_) died a few hours
after an uneventful labor. On autopsy the entire uterus was found
inverted and prolapsed, the organ the seat of a violent congestion,
the animal having died of shock.
[Illustration:
FIG. 22.—INVERTED AND PROLAPSED UTERUS. JAPANESE WALTZING MOUSE (MUS
WAGNERII ROTANS). UTERUS SHOWN LYING ON CARD.
]
THE PELVIS.
A study of the dynamics of the female pelvis from an evolutionary
standpoint may explain some of the difficulties attending parturition.
Starting from the biological law that morphology follows function and
that the anatomy of a part alters to suit a changed physiology with such
modifications as are necessary to fit each part properly to interact
with other structures comprising the entire animal, it is evident that
two great changes have occurred in the evolution of homo—the assumption
of the upright posture and an increase of intellectual power
necessitating a larger cranium of modified form. To this end also the
pelvis would have to change both for support and to allow the passage of
the enlarged head. The functions of the pelvis are (1) to attach the
legs or hinder limbs to the trunk; (2) to furnish points of attachment
and fulcra for the great muscles which move the limbs, and in the case
of man, hold the trunk erect; (3) to provide egress and support for the
terminal canals of the intestinal and urinary systems; (4) to provide
for a birth passage; (5) to act as a shelf and support for the abdominal
viscera. In quadrupeds the first four functions being perfectly served,
there are fewer abnormalities of reproduction (and in the positions of
viscera as well—ED.). In man natural selection weeded out narrow pelves,
but the present product is as yet an imperfect structure for one of its
main uses, parturition. It should be a funnel-shaped basin of the shape
of the fetal head and of the same height at all points—that is not
oblique, there should be no promontory, the pelvic symphysis should be
short and the sacrum of the same height. This would obviate internal
rotation now necessitated by the oblique pelvis; this does not occur in
quadrupeds.
Tracing the evolution of the pelvis, it is to be found first in fishes
where it is a loose disjointed, variable structure not attached to the
spine; in some it consists merely of ischia. In reptiles the box assumes
a form suggesting higher types. Passing from the toads to turtles and to
the crocodiles, the elements which go to make up the pelvis assume a
more and more osseous character and become more and more definitely
articulated with the spine or with the differentiated sacrum. Its
purpose in these low forms is mostly as a support for the muscles of the
legs and back. Birds present an advance in pelvic construction but with
a great preponderance of the vertebral column since thirteen to
seventeen bones may fuse to form a sacral “roof.” The ilia, ischia and
pubis are firmly combined. The box is long and narrow with a heavy part
for the acetabulum and broad surfaces for muscular insertions. The
pelvis of birds differs from that of cold-blooded vertebrates in the
greater number of vertebral segments entering into its composition, and
in their bony confluence. It differs from that of mammals by being
unclosed by an anterior symphysis and by a widely perforate acetabulum.
The ossification of the pelvic bones is to afford a support for the
legs, and the open pelvis allows passage of the large brittle egg. The
shape of the pelvis is of little importance in parturition in the
foregoing animals, except for birds which bear large eggs when the pubis
anteriorly is open for that purpose.
In monotremes one finds the reptilian type of pelvis with the three
divisions of the innominate bone remaining separate. The pelvis is
short, heavy and flat and is fitted with marsupial bones. The marsupial
pelvis, possessing parallel walls made by the ilia and ischia and a long
symphysis, resembles roughly a triangular prism. The sacrum is wedge-
shaped, without a promontory and has a considerable movability. The
marsupial bones are quite long. The triangular outlet is many times the
size necessary for the passage of the fetus.
The rodent pelvis is difficult to summarize morphologically by reason of
the great diversity of form occurring in the many genera of the order,
but it may be said that here the pelvis is usually of a type rather
higher in the scale than the other structural characteristics of the
order would indicate. The outlet is more commonly ovate than
rectangular, the ischia and ilia lie at a more marked angle to each
other, and the true conjugate forms a lesser angle than is common in
quadrupeds. The sacroiliac joint is, in general, freely movable.
The female insectivorous pelvis is relatively large, the sacroiliac
junction usually being long and well knit while the pubes are slender,
wide of angle as to their descending rami and there may be no symphysis,
as in bats. Edentates have distinct bony unions of the elements of the
innominate bone and of this to the sacrum which increases in width
downward permitting a long synostosis with ischia and pubes; these
joints are not movable. The pubes are slender and the symphysis short.
The sacrosymphyseal angle is 80 degrees in the armadillo. The inlet is
roughly triangular to almost round. Cetacea have no clearly developed
pelvis, its place being represented by two long bones, larger in males,
which seem to be the insertion of the genital erector muscles. There is
no junction to form a pelvis nor is there an acetabulum. A pelvic box is
absent in the Sirenia, but lateral processes from the lumbar vertebræ
form a sort of ileum between which an ischium is located.
Proboscidea have a massive pelvis lying vertical to the spine. The iliac
alæ are wide and deeply concave; the ischia are short, heavy and
parallel to the ilia; the pubes are short and combined in a heavy
symphysis; the sacroiliac joint is short, heavy and slightly movable;
the outlet is ovate. In one specimen examined the length was 4 feet,
symphysis 18 inches, true conjugate 19 inches, transverse diameter 17.5
inches; crests of iliac were 28 inches long.
Perissodactylic animals throughout this suborder have similar pelves
except in so far as the obliquity is concerned. In the rhinoceros it is
90° with the spinal column, in the horse 135°; the angle of the true
conjugate is 10° in the former, 50° in the latter. The lateral halves of
the box are heavy and parallel; the symphysis is short in the
rhinoceros, large in the horse; the outlet is ovoid. Artiodactyla,
including pachyderms and ruminants, show a variety of shapes and
constructions. Hippopotami have a short massive box tilted at about 150°
from the spine, with widely flaring ilia and ischia; the pubes are
slender but not combined in a strong symphysis. In ruminants the sacrum
consists of four fused units; the sacroiliac joint is fairly movable;
the obliquity is about 145°; ilia are long and slender and flaring; the
ischia are broad and parallel with the ilia; pubes are slender but form
a symphysis about two-fifths the total pelvic length; the infrapelvic
angle is wide; the outlet of the pelvis is almost rectangular.
The general characteristics of the carnivorous pelvis may be summarized
as consisting of a long strong symphysis, parallel lateral pelvic walls,
a great sacrosymphyseal angle, and a marked separation of the bodies of
the ischia. The sacroiliac joint is in general moderately movable.
The pelvis of lemurs is narrow, attached lightly to the slender sacrum,
tilted at an angle of 140° and is possessed of a short weak symphysis;
it resembles the structure in bats. In macaques the box is long, the
sacrum wide, with a short iliac synostosis, the ilia long, narrow and
curved out sharply, the ischia are continuous with the ilia and widely
separated; the symphysis is short, about one-sixth the pelvic length;
the angle of the superior strait is about 60°; the outlet is oval, the
transverse diameter being short. The chimpanzee pelvis is made up of a
wedge-shaped sacrum composed of three vertebræ, wide, flaring, concave
ilia, stout well separated ischia with flattened tuberosities and a
short symphysis parallel to the sacrum; the outlet is ovoid; true
conjugate angle is 65°; the sacroiliac junction has little motility. In
the gorillas the following points differ from the last described
structure. Five vertebræ comprise the sacrum and the anterior surface is
distinctly concave; the pelvic contour while still ovoid, has the two
diameters more nearly equal; the pelvic angle is obtuse; the true
conjugate is at an angle of 70°.
In man the salient features of the pelvis are—a broad, wedge-shaped
sacrum, concave anteriorly, with wide articular surfaces and a limited
motility; widely flaring ilia including the concave curvature of the
body of the bone whereby the lateral diameter of the pelvic inlet
becomes wider than in lower orders; short stout pubes with a narrowed
angle beneath them; heavy blunt ischia with large tuberosities; true
conjugate is at an angle of 55°. The human fetal pelvis resembles that
of quadrupeds.
Study of these data indicates that the quadruped pelvis retains many
things in common through all the orders especially in being a roughly
rectangular structure lying chiefly horizontally, with a poorly
developed false pelvis, straight ischia and a long symphysis pubis; the
angle of the true conjugate is greater than in man and may be up to 80°.
The long pubic synostosis changes the relation of the true and diagonal
conjugate, but the former is no indicator of pelvic capacity, since in
lower mammals the promontory of the sacrum lies anterior to the
symphysis; the vertical diameter is a better measure of pelvic size and
form. Sacral movement seems greater in lower animals especially in
youth. The shape of the pelvic inlet is triangular in the lowest forms,
the posterior base of this becoming wide as one ascends in a zoological
line; the concavity of the ilia also increases so that the higher the
animal the more curved are the lateral borders. In quadrupeds the
anteroposterior diameter is greater than the lateral; the reverse is
true in man. The long straight-sided quadruped pelvis is retained
because of the direction of the forces from the legs, which is as much
or more upon the anterior or pubic arch as upon the sacroiliac junction.
In the semiupright position of the monkey the force is directed backward
and downward upon the sacrum, this aiming to widen the pelvis by forcing
the ilia apart. The effect of the upward force from the femora is to
throw the pelvis upward and anteriorly by directing the line of action
through the acetabula more toward the ventral surface. The sacroiliac
ligaments hold the ilia firmly, their alæ being spread outward by the
force from above. Elevation of the pubes shortens their symphysis and
the true conjugate. By these changes the birth canal is shorter,
entirely bony, with the upper inlet on the same plane, and promontory
and symphysis are near enough the same level to be met at the same time
by the engaging head. In these pelves the anteroposterior diameter is
still long and superior rotation is not necessary.
In Man the force exerted on the pelvis from above is greatest among all
animals and is greater when he is in active motion. The force is
directed from above to the sacroiliac joint, the iliac bodies and the
acetabular region while from below the pressure is directly exerted upon
the last named. The force from above rotates the sacrum downward at its
upper end, the attached sacroiliac ligaments at the same time pulling
the alæ inward and throwing outward the lower end, the acetabular part.
This tends to widen the pelvic box and to reduce its anteroposterior
diameter. But the force acting from the legs and the adductors of the
thigh push the lower parts of the ilia and the ischia and pubes apart,
thus counterbalancing the effort of the force from above. The combined
forces tend to bend the iliac bodies, thereby producing the curved
lateral margins of the superior strait and making the lateral axis long.
As between these two forces that from above is certainly the greater.
The effect of these forces can be followed by comparing a quadruped
pelvis, a human fetal pelvis and an adult human one. The first two are
similar chiefly in the shape of the inlet and the flat character of the
ilia. This is strongly corroborative of the evolutionary development of
the pelvis to meet the demand of the upright position. The effects of
this evolution are as follows: First, to develop a forward inclination
of the sacrum and a concavity in its surface anteriorly, second to
increase greatly the iliopubic and ilioischiatic angles, third to cause
the acetabula to move forward of the lumbosacral axis, fourth to shorten
the bodies of the ilia and to develop in them a regularly curved
surface, the concavity of which faces forward and inward, fifth to
decrease the interpubic angle and accordingly to remove the triangular
quality of the pelvic contour, sixth to increase the transverse diameter
at the expense of the anteroposterior, and seventh to decrease greatly
the sacrosymphyseal angle with the result that the entire pelvic cavity
lies in one plane.
The effect of forces in alterations of the pelvic architecture may be
seen in their several stages by the observation of the mammalian pelvis
in the course of its evolution and development. The transitions in form
are very gradual, but their gradations are well shown in the
characteristic forms which have been described; the quadruped, monkey,
anthropoid ape, human fetal and adult human type.
By an examination of the adult pelvis and fetal skulls it will be seen
that the shape of the quadruped birth canal accommodates the fetal head
nicely when in extension since there is no large posterior cranial
development, the head and neck being of nearly the same thickness. In
the monkey, where the facial angle increases, the head does not advance
as a pointed presentation but as an irregular surface—the chin, forehead
or occiput. It is only when the head has assumed a high facial angle and
a well developed occipital lobe and the pelvic inlet has become
transversely wide, that internal rotation is necessary.
Resuming a discussion of our records I shall at this place introduce
additional cases of pathology in the parturient genital organ and then
discuss the general system. Beside the cases of dystocia discussed in
preceding pages there occurred in a deer a complete eversion of the
uterus, which was incompletely involuted, accompanying prolapse of the
rectum and bladder due to straining after severe injuries, probably
inflicted by a male. The animal lived long enough to develop a purulent
cystitis which spread to the vagina, uterus and pelvic soft parts. The
left uterine cornu of an American bison was found to contain a
decomposing fetus at about half term; general sepsis had supervened
which led to the animal’s death in about a week, according to the
keeper’s observations. The history of a monkey, followed through two
pregnancies and finally dying of tuberculosis and sepsis is interesting.
Pigtailed Macaque (_Macacus nemestrinus_). Received March 5, 1903,
died October 29, 1904. This animal gave birth on December 28, 1903 to
a young one which appeared feet first; the arms appeared to have
penetrated the septum between the vagina and rectum and protruded
through the anus. Had to be cut off before delivery. She had a second
young one October 21, 1904, which was properly delivered but was weak
and lived two days, having received little attention from the mother.
The mother since has been weak in the hind legs, eaten almost nothing
and several times has passed a little blood in the stool. Lungs are
partially collapsed; contain scattered small pinhead tubercles; right
lower lobe contains a caseous nodule about the size of a cherry. Both
pleuræ contain clear fluid. Abdomen contains a half pint of cloudy
fluid. Omentum adherent along lower border and region of spleen and
contains pinhead tubercles. Surface of the liver is studded with
numerous pinpoint, pinhead and (old) pea sized tubercles. Some places
in the liver seem to be the result of two invasions. Spleen presents
small cherry sized tubercles thickly grouped together leaving small
amount of splenic tissue to be seen. Kidneys contain pinhead to barley
grain tubercles. Uterus is somewhat enlarged. External surface smooth.
Section shows wall to be about one-quarter inch thick. Uterine cavity
enlarged. Considerable bloody pus in uterine cavity. No communication
can be found between the bladder and the vaginal wall or between the
vaginal wall and the rectum. The intestines are negative. Mesenteric
glands enlarged and caseous.
Abortion and miscarriage are occasionally seen in the monkeys, rodents
and ungulates. The underlying reason for this can seldom be determined.
A few cases seem to depend upon annoyance or abuse by cage-mates, a few
to immaturity of the mother and some others seem the result of bone
diseases such as osteomalacia. It does not occur regularly in any group
or enclosure and appears to have no comparative pathological value.
Injuries of the external genitalia of the nature of lacerated wounds are
occasionally seen in ungulates and carnivores, but never in monkeys.
Acute vaginitis, sometimes localized into an abscess of the wall has
been known to follow these traumata. Chronic changes have been met but
once, which example will be detailed under another heading.
INFLAMMATIONS.
Endometritis has been observed sixteen times, as follows: Carnivora 10,
Rodentia 3, Ungulata 2, Edentata 1. In searching for causes it was found
that the association with a recent delivery of young, an abortion or the
retention of a fetus, was responsible five times. Association with
tumors of the uterus was noted four times. Injury preceded the condition
on two occasions, while one instance seemed to be hematogenic, being
secondary to a septic pneumonia. On four occasions the actual cause
could not be established with satisfaction. Pathologically the traumatic
and parturient cases were purulent while tumors seemed to produce a more
exfoliative or hypertrophic inflammation.
Inflammation of the Fallopian tube has been observed but five times, and
only in one of these did the uterine wall fail to participate in the
disease. The animals affected were three carnivores, one rodent and one
marsupial.
No particularly important association of this salpingitis and other
pathology was noted, and indeed the only noteworthy lesion of the organ
under discussion is now to be cited.
Nylghaie (_Boselaphus tragocamelus_). Chronic vaginitis, fibroma
uteri, chronic tuberculous salpingitis. The vulva and lower half of
the vagina are covered by a thin coating of yellowish mucus. Mucosa is
mottled purple, irregular, in some places smooth and flat, and in
others showing clear cysts with yellowish fluid contents. The upper
part of the vagina shows a pedunculated fibroid extending from the
cervix. This tumor measures 32 × 20 mm., and is attached to the
posterior cervical wall by a broad pedicle and is of smooth surface.
The right uterine wall shows a large fibroid which twists the uterine
lumen to the left. The tumor in the right uterine cornu is nodular,
measures 11 × 9 × 7 cm., shows many dilated veins coursing over the
surface and one section shows a soft central necrotic area. The left
uterine cornu shows a small fibroid at the lower end. There is a
chronic endometritis present. The outer half of the right tube is the
seat of firm nodular swellings, one of which proves to be a purulent
salpingitis (tuberculous), the others calcareocaseous salpingitis.
Both ovaries are fibroid and cystic. Microscopic section shows some
exfoliation of the epithelium of the vagina. The uterine cornu is
thickened and the fibrous tissue is greatly increased. The tube is the
seat of a purulent salpingitis with an occasional broken down tubercle
present. The ovaries show a mild degree of oöphoritis (Fig. 23).
OBSTRUCTIONS TO CONTINUITY OF BIRTH CANAL.
Obstruction to the lumen of the genital canal was observed in three
mammals.
An American Bison (_Bison bison_), five years old and known to have
been in captivity three years died of a chronic gastroenteritis and
pulmonary parasites after many weeks of failing health. At autopsy a
double hydrosalpinx, and probably unilateral hydrometra, with low
grade cystic oöphoritis were found. A picture is reproduced. The notes
are not perfectly clear as to the anatomy but from the gross specimen
in preservative it would seem that the left uterine cornu was involved
in the dilatation (Fig. 24).
[Illustration:
FIG. 23.—PEDUNCULATED FIBROMA OF CERVIX; INTRAMURAL FIBROMA OF UTERINE
BODY; FIBROMA OF LEFT UTERINE CORNU; TUBERCULOUS SALPINGITIS AND
MURAL METRITIS RIGHT SIDE. NYLGHAIE (BOSELAPHUS TRAGOCAMELUS).
]
[Illustration:
FIG. 24.—DOUBLE HYDROSALPINX AND UNILATERAL HYDROMETRA. BISON (BISON
BISON).
]
Lion cub (_Felis leo_) had congenital cystic uterus. The only
abnormality found is in connection with the internal genitalia. The
vagina is 50 mm. long, uterus 23 mm. long, horns of uterus each 90 mm.
long. The diameter of the uterus measures 10 mm. in both body and
cornua, the latter being distended by clear watery fluid. They are
symmetrically curved downward. They show no adhesions or obliteration
of the os uteri to account for fluid retention. The probe is readily
passed from the vagina to the end of the uterine horns. Vagina is
patulous through its whole course. Ovary and tube normal.
An Axis Deer (_Cervus axis_) showed congenital hydrometra. This
specimen is from a day old animal, consists of the genitalia in which
the entire body of the uterus and both uterine cornua have been
transformed into a thin-walled translucent cystic cavity containing
clear fluid. The body of the uterus measures 15 mm. diameter, each
cornu reaching the diameter of 5 mm. The cornua are curled not unlike
ram’s horns, and are united by a line of adhesions above the body in
the midline. From the ends of the convoluted and cystic uterus and
cornua spring the normal tubes each with its ovary.
CYSTS.
Cysts have not been noticed in the lower genital canal, but it is true
that this region is not exhaustively studied in routine autopsies;
however, no large cysts have occurred there. Cysts of the ovary have
been limited to the so-called cystic disease of this organ; one
parovarian cyst has been found. These animals, two ungulates, two
carnivores and a rodent, are noted as being young adults, only one of
which was known to have borne young. In only one, the rodent, was there
evidence of chronic peritoneal disease. The notes of the parovarian cyst
case are as follows:
An Aoudad (_Ovis tragelaphus_) showed a ruptured parovarian cyst with
normal right side pregnancy. The fetus, its placenta and membranes
show no change. The right broad ligament and ovary are negative, the
latter containing a red and gray corpus luteum. The left ovary is
fibrotic and the left ligament is the seat of a large hematoma, which
on section is found to contain thin sheets of gray translucent
membrane, like walls of a cyst. The vessels are all distended.
Arteries have stiff walls and are empty. Veins have well formed clot.
The whole uterus and adnexa were slightly turned to the right, but the
twist does not seem to have been sufficient to cause rupture of a
broad ligament vessel. Microscopic section of the broad ligament shows
a parovarian cyst into which there has been hemorrhage. The cyst is
separated from the ovary proper by a short band of tissue which
apparently consists of thinnedout ovarian cortex.
TUMORS.
Tumors of this tract in the mammals have been confined to the uterus
proper, none having been found in the vagina, tubes or ovaries; in birds
one oviductal growth and two ovarian tumors are recorded. These tumors
are reported briefly according to their histological structures, a brief
summary being added at the end.
A Black Lemur (_Lemur macaco_) showed a local leiomyofibromatous
nodule on the lateral aspect of the uterine body near the cornu.
A nine banded Armadillo (_Tatu novemcinctus_) gave an interesting
specimen which can be described as follows: The uterus is enlarged so
that it measures 90 mm. from external os to fundus. Tubes and ovaries
apparently normal. There is considerable grumous blood in the vagina
and cervix; the former is normal. The cervix is pale and opaque in its
lower half; upper half is slightly congested and mucosa decidedly
rugous. The uterus itself shows an attenuated muscular wall with a
thickened irregular mucosa which is the seat of pseudomembranous tabs
of a dull red color, while the mucous membrane itself is irregularly
red and yellow; also some grumous blood in the cavity. The size of the
uterus is due to a large fibroma attached to the left lateral wall
near the cornu. The mucous membrane of this is irregularly disturbed
in some places, the tumor being partly bare. Here and there the mucous
membrane shows the same degenerating hypertrophic character as seen on
uterine wall. The tumor is attached to the wall by a narrow peduncle
(Fig. 25).
A nylghaie with multiple fibromata has already been described.
A Jaguar (_Felis onca_) presented in the middle of the right uterine
cornu a cystic resilient tumor 3 × 4 cm., which proved to be a
fibroadenoma.
A lioness (_Felis leo_) presented a penetrating malignant adenoma of
the uterine cervix upon which an active endometritis was implanted.
The tumor penetrated the uterine wall, which gave way, an acute fatal
peritonitis resulting. Metastases had occurred to the lung.
A Wild Boar (_Sus scrofa_) had a generalized ulcerating carcinoma of
the uterine body.
An instance of chorionepithelioma in a Canada porcupine is worthy of
separate description.
[Illustration:
FIG. 25.—PEDUNCULATED FIBROMA UTERI. NINE BANDED ARMADILLO (TATU
NOVEMCINCTUS).
]
[Illustration:
FIG. 26.—FIBROMYOMA OF UTERUS. CORNUA AND TUBES. INDIAN ELEPHANT
(ELEPHAS INDICUS). WHOLE MASS AS MOUNTED ON BOARD. IT MEASURED WHEN
FRESH ABOUT SIX FEET ACROSS.
FIG. 27.—CROSS SECTION OF CORNU OF Fig. 26 AT HIGHER POWER. A PIECE
CUT OFF WHERE THE PALE AREA SHOWS ON THE RIGHT CORNU OF THE OTHER
FIGURE.
]
Canada Porcupine (_Erethizon dorsatus dorsatus_). Acute suppurative
catarrhal endometritis, hemorrhage in myometrium, chorionepithelioma.
In anterior abdominal wall a short quill was found imbedded. A very
small quill was imbedded in the retrocervical muscles. A quill about 2
cm. long lies free in the peritoneal cavity attached by recent plastic
adhesions to peritoneum over left pubic ramus. A fourth quill was
adherent by recent fibrous lesions to anterior wall of cecum.
Peritoneum contains a moderate excess of thin watery fluid. Liver and
spleen are negative. Kidney is large, greenish yellow, firm, smooth
and glistening. The right uterine cornu is subinvoluted (the animal
was delivered of a fetus before arrival at the Garden, which was
sixteen days before death). Its walls are thick and distinctly
congested, the congestion being of inflammatory type. Microscopic
section of uterus shows a regular, not ulcerated serosa. Subjacent
fibrous tissue is loose and contains a granular precipitate together
with a few red blood cells. Muscular bundles under this are widely
separated evidently partly by trauma, but certainly also by edematous
interstitial tissue in which fibrillæ are widely separated and between
which free red blood cells and plasma cells are seen. Capillaries
ramifying through muscular bundles are greatly distended and
congested. Numerous large arteries are present in addition. Some of
these contain pink granular material within their walls together with
diffuse collection of red blood cells. Fibroblasts extend into this
necrotic mass from other sections of the walls. Lumen of such arteries
is diminished and in places quite obliterated by recent organization
tissue. At many places in muscularis are large cells of irregular
rounded form and some cytoplasms incline toward the basic tint with
one or several large hyperchromatic nuclei. They are especially likely
to occur close to a capillary. There is an especially large
accumulation of these cells at that point of section farthest from
fundus. Here these cells occur in chord-like masses which infiltrate
the muscularis both internally and externally. This particular mass
lies in the muscularis internal to great arteries and well removed
from mucosa. In this mass are giant cells with multiple nuclei
scattered through the whole cytoplasm together with smaller cells with
exceptionally large hyperchromatic nuclei. Subepithelial tissue is
especially congested and contains numerous fibroblasts together with a
few well formed glandular acini. Lining epithelium is discontinuous,
of simple tall columnar type, in places becoming flattened or even
lost. Lumen of organ is practically completely occupied by pus.
The Indian Elephant “Empress” (_Elephas indicus_) showed calcified
fibroids of the fimbriæ; gross and microscopic notes and a photograph
are given. The uterus is bicornate in type. In its body there are
numerous fibrous nodules 1 to 4 cm. diameter. They can be traced from
the cervix to the ends of both horns and tubes. At the end of each
tube there is a great mass of calcified partly conglomerate tumors
some of which are partly, others quite, pedunculated. One specimen
measuring 2 × 1 × 1½ cm. has a peduncle 15 cm. long. The mass on the
right side weighs 3,926 grams, that on the left side about the same.
Section of tumor from uterine cornu shows the classical appearance of
a leiomyoma with usual whorling and interlacing bundles of involuntary
muscle fibres. Degenerative and vascular changes not seen nor is there
any notable addition of fibrous tissue. This latter tissue is shown
only in small amounts at one end of section.
The preceding data record the discovery of three fibromata of the uterus
and one of the fimbriæ; one fibroadenomata of the cystic type, one
malignant adenoma, one adenocarcinoma, and one chorionepithelioma. They
were found in Lemures 1, Carnivora 2, Ungulata 2, Proboscidea 1,
Rodentia 1, and Edentata 1. Metastases occurred but once, to the lung.
No secondary tumors were found in the uterus.
While upon the subject of neoplasms of the female genitalia, it may be
well to describe the three instances found in the avian organs. A very
definite case of adenocarcinoma occurred in the oviduct of an Undulated
Grass Parrakeet (_Melopsittacus undulatus_), a variety of bird very
susceptible to neoplasms. The notes in an abbreviated form are given:
Immediately under the ovary is an irregular mass measuring 2 cm. long,
1 cm. wide, 1 cm. deep. The lower part of the tumor thus comes to
press against the cloaca. It is adherent anteriorly to the peritoneum.
It apparently consists of two parts, an upper rounded larger, and a
lower spherical smaller. Both parts are well encapsulated and
separated from each other by a well defined constriction. The upper
part has a pale opalescent appearance. It cut easily with moderate
resistance. The lower portion externally has an egg-yellow color
streaked with red. Upon section it has the same general appearance but
contains in addition numerous small, irregular, yellow areas which
mask the general opalescent appearance. The centre of this node
contains an empty space (cyst) 1 × 2 mm. Microscopic section consists
of an oval or elliptical mass showing over one convexity a depression
simulating a constriction. A thin fibrous capsule extends over most of
the section which is extra thick at the point of constriction.
Constriction roughly divides the section into two. The upper portion
consists of one or two coarse septa of fibrous tissue. From these
central areas a delicate connective tissue framework extends
peripherally. In this framework are great numbers of irregular gland
spaces. These gland spaces are so closely placed in most cases that
room is afforded for but one nucleus of the bundle. The gland spaces
vary in size, some large, some small, and show grotesque shapes. The
larger gland spaces here contain granular debris and pyknotic nuclei.
Compound granule cells suggesting colostrum corpuscles may be seen in
this debris. The epithelium of the gland spaces consists of a single
layer of columnar epithelium of low cuboidal type. In places it is
heaped up so as to present several layers. In places too it is not
applied in a regular manner to the basement membrane but breaks
through and then the cells extend in most disorderly fashion into the
lymphatics of the stroma. At these points the nuclei are
hyperchromatic. The lower portion follows closely the description
given above save that the glandular spaces are much larger. They
contain pink glandular material with admixture of compound granule
cells. At the convexity of the tumor the acini are especially large.
Here they contain a pink granular material which stains more intensely
than the other granular contents and, too, inside of this intense pink
material are sharply circumscribed areas of yet more intensely pink
staining material. This latter substance has a streaming appearance
under the high power. This streaming appearance is due to elongated
areas of less dense material which are placed with their long axes
parallel. This lower portion shows, furthermore, even with the naked
eye, two large cysts which are lined by epithelium and contain a very
small number of compound granule cells. The capsule at the lower pole
is worthy of note from the extreme dilatation of its capillaries.
[Illustration:
FIG. 28.—PAPILLARY ADENOMA OF OVARY. WILD TURKEY (MELLEAGRIS
GALLOPAVO).
]
A papillary adenoma was found in a wild turkey (Fig. 26) and a mixed
cell sarcoma in a King parrakeet (_Apromictus cyanopygius_). None of
these tumors sent out metastases.
Interest in the avian reproductive tract from a pathological standpoint
centres around the tumors as already given, and abnormalities in egg-
bearing. Among our specimens there have been many cases of soft shelled
eggs apparently blocked in the oviduct, of “egg-binding” and of the
inspissated-egg-remains in the abdominal cavity. These conditions are
well known to veterinarians and are explained on the basis of improper
food, immaturity of the bearing fowl, injury and inflammations of the
cloaca and oviduct. I made an attempt to associate these conditions with
infectious disease incidence and with the normal egg size. The results
are not harmonious. No relation existed between general or local
infection and any of these conditions. Gallinaceous birds with their
large eggs show the highest percentage (2.3 per cent.), but Anseres with
a somewhat larger relative egg size show 1.6 per cent. Passeres, with
eggs of very variable size but relatively large pelves, have an
incidence of .6 per cent. Struthiones’ eggs are relatively small; their
incidence is 1.5 per cent.
Salpingitis occurred in seven cases, but there have been no evidences of
an acute infectious disease such as is responsible for gleet.
THE MAMMARY GLAND.
This structure has been the seat of three inflammatory conditions and
four tumors. The former occurred twice in nursing animals, one of which
seemed to be suffering with distemper, another from puerperal sepsis,
while the third case was probably traumatic. The animals were in order,
a raccoon, a coati and a skunk. Four cancers of the breast have been
observed, all richly cellular or glandular in type; none of the
scirrhous variety has been encountered. Two of them were ulcerating and
one was about to become so. One gave extension to the axilla and lung,
one had penetrated the abdominal wall and grown around the kidney; the
remainder had not yet extended. The animals were Black Bear (_Ursus
americanus_) (thoracic mamma with extension), Common Opossum (_Didelphys
virginiana_) (two sections of breast in pouch), two White footed Mice
(_Peromyscus leucopus_) (posterior abdominal right gland and whole
side). These animals were all adult but not old.
[Illustration:
FIG. 29.—ADENOCARCINOMA OF MAMMARY GLAND (TWO SECTIONS WITHIN POUCH).
COMMON OPOSSUM (DIDELPHYS VIRGINIANA).
]