Mi.MOIR ON THE REPRODUCTION OF THE OPOSSUM. ] 65 



lebcnskraft — since, but for such special endowment, its placentoid would not be so early 

 exchanged for its pulmonary and gastric sources of nutrition and oxygenation. Probably 

 all the marsupiata are endowed with extraordinary tenacity of life. 



The liver is immense. 



The diaphragm strong. 



Lungs still vesicular and bubble-like, but less so than in the earliest case. The pulmo- 

 nary organ is evidently acquiring greater consistence, and a more visceral or parenchy- 

 inatous character. 



Many large sanguiferous red vessels seen on the skin on each side of the neck, 

 ramifying on the head — along the arms; on the sides — and on the dorsal aspect of the 

 tail, with arterioles, or venules branching from them. 



The heart in a strong pericardium, more on the left side. Heart and pericardium 

 together near three-twentieths of an inch in length. 



Liver very large, of a dark hue, extends far over on the left side; from beneath which 

 half peeps the distended stomach. 



Intestines very full, and yellow-tinted, from the yellow gall mixed with ihe milk of the 

 convolutions. Hence the animal already has a biliary apparatus for abundant secretions 

 of bile. Dr. Thomas Schwann has shown, by his experiments on the dog. that bile being 

 absent, the animal becomes atrophied. How fully is this creature endowed with all the 

 means of nutrition, both of apparatus and elements! 



The members of the society have now an opportunity to examine the dissected animal, 

 now on the table, and may see that the representation in my drawing is correct. 



The mode of arrangement of the stomach and intestines will be found as in the figure. 



The bladder of urine large, and full — very white. 



The tongue has become relatively smaller than in the first case. 



It is thought very desirable that some proofs should be forthcoming as to the method 

 or machinery by which the young arc transferred from the uterine to the marsupial 

 gestation. 



I believe this desideratum, if it really be one now, — will never l>e attained. It is clear 

 that the paw of the dam cannot do it; the vulva cannot touch the orifice of the pouch j 

 the young cannot creep to the pouch. It remains, then, that the lips of the dam are used 

 to place them. 



I shall trespass no longer on the patience of members, than by offering the remark, 

 that these researches appear to clear up a lingering doubt and uncertainty as to the 

 nature of the earliest marsupial life. They show it to be a chylopoietic, warm-blooded, 

 oxygenating, innervating, and free-willing life; and that all the means of carrying on an 

 independent life arc as fully enjoyed by the marsupial foetus, as by the young of the 

 elephant at the teat, or the balama mysticctus, which is said, at birth, to be twenty-sev< p 

 feet in length. If that be so, all mystery as to marsupial life is at an end — save that 

 useless one, of the machinery of adaptation to (he nipple. 



Whether she mere!) depositee them inside of the marsupial sphincter, leaving them to 

 find the nipple instinctively — which is probable — or whether she applies them herself — 

 which is an incredible accuracy of contact and perception — no man can ever know, since 

 vol. x.— 38 



