2i6 Doyle, A Note on Parturition in Perameles. [v^k^'xxx 



gaps. The pubic bone on the right side was found to be 

 In'oken. The pubic symphysis was then divided, and the whole 

 genito-urinary system dissected out. The system was then 

 examined very carefully with the aid of a powerful liand lens 

 to see if there were any deficiencies in the walls of the different 

 viscera. None were found. Then, by the aid of a l)ristle, the 

 absolute and direct continuity of the vaginal canal with the 

 uterus was proved. Thus the holes in the pouch were seen to 

 open into muscle only, and, since they had no connection with 

 the genital organs, it is obvious that they could have nothing 

 to do with parturition, and could have neither a direct nor 

 even indirect effect on that function. The breaking of the 

 bone seems to point to the trap, as the specimen was a trapped 

 one, or else to a severe accident. The accident causing the 

 fracture may very possibly have caused the tearing in the 

 muscles and skin, resulting in the irregular openings in the 

 pouch and the marked laceration of the thigh muscles already 

 mentioned. 



On reviewing the theory already formulated and the in- 

 vestigation now finished, the following points seemed to the 

 observer to clinch the argument, and satisfactorily and com- 

 pletely to disprove the theory — 



(i) The inguinal canal is never open after birth. If it is, 

 it is a pathological condition, and not due in any 

 way to a normal physiological function. 



(2) If the inguinal canal did remain open, all that could 



pass down into it would be a loop of intestine, forming 

 a hernia, and hernia is rare, if not unknown, in 

 quadrupeds. 



(3) The fact of the openings closing after parturition is 



questionable, because, from their size, the time elapsing 

 between two successive pregnancies of the animal 

 would not be long enough for them to heal. 



(4) The presence of two such weakenings in the abdominal 



wall would be a source of great danger to the animal 

 when undergoing any unusual strain. 



(5) Peritonitis would very probably supervene if such 



openings as were in the pouch were in communication 

 with the abdominal cavity. 



So the results of the investigation disprove absolutely the 

 theory outlined, and maintain the older and correct idea of the 

 genito-urinary system as described by zoologists. 



In conclusion, I would like to set a problem to all who believe 

 the original theory : How long would the genus Perameles — 

 or any other genus— last if the act of parturition resulted in a 

 fractured pelvis, as the theorist in this case, anyway, seems 

 to demand ? 



