292 DISEASE IN WILD MAMMALS AND BIRDS 
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 success- 
fully 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 ineffec- 
tual attempt was made to deliver by version, the monkej'^ 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 placentae 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 umbili- 
