178 EDWARD MOCRADY, JR. 



into thinking that he had observed parturition when he really 

 had not. 



On January 28, 1847, Michel observed the copulation of two 

 opossums, and 14 days and 17 hours later he observed what 

 he described as follows : 



The pregnant female was found standing on her hind legs ; 

 her body was much bent, and propped up against the corner 

 of the cage ; her muzzle in immediate contact with the cloacal 

 opening, which was red, tumified and distended; a young 

 appeared at the opening, and was conveyed by the mother's 

 mouth to the pouch, or perhaps was rather licked in, as her 

 tongue seemed busily employed within, around and about 

 the pouch. 



The details which make this account questionable are 

 several. In the first place, the period of 14 days and 17 hours 

 is about 2 full days too long for normal gestation. As men- 

 tioned in a previous section, it is unlikely that the period 

 varies more than a few hours. A variation of 2 days is cer- 

 tainly abnormal, if possible at all. 



In the second place, the external genital region is not 

 'tumified and distended' at the time of parturition,; though to 

 one not thoroughly familiar with its appearance, it might 

 easily appear to be so at any time, for it always has a 'swollen' 

 appearance. That he was not very familiar with its ap- 

 pearance is definitely shown by his reference to the 'cloacal 

 opening.' A closer observation would have shown him that 

 there is no cloaca at all in the opossum. The urinogenital 

 orifice and the anus open separately to the outside (fig. 5). 

 Finally, the wording of his last sentence clearly expresses un- 

 certainty about what he saw. The female was licking the 

 perineal region, the lower abdomen, and the inside of the 

 pouch. The young that he thought he saw at the opening 

 may very reasonably have been the tip of the mother 's tongue, 

 for I have often seen it when it could easily be thus misinter- 

 preted. It seems rather likely that the young he found in the 

 pouch had been born about 2 days previously, and all he ob- 

 served was the mother grooming herself. 



