329 



Examined by a lens, it respired by two nostrils and by the mouth. 

 It died at ten minutes past nine o'clock, which was one hour and 

 twenty-nine minutes after its separation, though exposed for some 

 time to the cold air of the street. 



The tongue was apparently equal to one-third the magnitude of 

 the head — milk white, grooved so as to embrace half the cylindrical 

 circumference of the teat, which was pressed, as to its other half, 

 against the vault of the palate. The mouth was a pore, which I 

 could not distinctly discern without a lens; the cavity of the mouth 

 spacious. The diaphragm strong. 



The heart, in its pericardium, large and powerful. The liver very 

 large. The stomach filled with milk vesicles, examined in the mi- 

 croscope; the intestinal convolutions distended with milk and chyle, 

 stained yellow with bile; the bladder of urine filled with fluid. 



Two lungs, each consisting of minute transparent vesicles resem- 

 bling small soap bubbles. 



Such is the anatomy of the young opossum of three and a half 

 grains, destined to attain a weight of fifteen or sixteen pounds. 



While lying on the watch glass, I put the smooth point of a pencil 

 to its stomal pore. The animal sucked at the pencil, and held on so 

 firmly, that J could lift it partly off the glass by it. 



Does this fact show that twenty-four hours earlier it could draw 

 the delicate teat into the orifice ? 



The young, having the teat once in the mouth, cannot let it go; 

 nor does it abandon it for many days. It adheres as the bitch ad- 

 heres to the male organ of the dog. 



I could discover no trace of an umbilicus. I sought for it with a 

 good doublet. But it is not to be believed that a breathing, sangui- 

 ferous, digesting mammifer, can be developed independently of a pla- 

 centa. 



On Monday, March 12th, an animal being removed for dissection 

 weighed twelve grains ; it breathed thirty-two times per minute. 



March 18th. A young one weighed eighteen grains. The tail 

 very prehensile. 



I immersed it in a cup of alcohol to kill it for dissection. It did 

 not die in the fluid until it had been immersed in it for sixteen mi- 

 nutes. 



The observations show the marsupial young to have a chylopoietic, 

 warm-blooded, oxydating, innervating, and free-willing life, being as 

 fully endowed with all the means of an independent existence, as the 

 young of the elephant at the teat. 



