164 MEMOIR ON THE REPRODUCTION OF THE OPOSSUM. 



At 1 1 , p. m. it was still alive and strong, and, I doubt not, might live until morning, or 

 longer. I now suspended it in alcohol, in which fluid it continued to move its body and 

 arms for five minutes, and then died. I sent it to Professor Louis Agassiz, at Boston. 



Tuesday, March 16th. — No hairs on the young, which are grown considerably, and 

 quite strong and lively. 



Thursday, March 18th, twelfth day. — The figure represents truly the opened marsupium. 

 I removed an embryo, which held on more strongly than the others. Its weight, in Mr. 

 Bringhurst's scale, is 18 grains; which is more than four hundred per cent, of increase. 



Flexed .75 of an inch long; extended, from snout to tail, 1.25 inches. 



No hairs. 



Skin very loose and wrinkled. It seems to me that the development of its derm is 

 much more hasty than that of any other tissue — as if it were the forerunner of the organs, 

 growing more rapidly than they, in order for their accommodation. Nails begin to grow 

 on the hind toes. Intestines visible through the still translucent, rose-coloured skin. 



Scrotum large. 



Motion of tongue and also of the inchoate lower maxilla visible in sucking; which I 

 noted as it imbibed and swallowed milk from the end of a camel hair pencil moistened 

 with milk. The point of the pencil seen through the translucent cheek within the mouth. 



The outer ear of an oval lenticular form, whitish, is still closed, being completely 

 covered with skin. 



Globe of the eye seems much larger; no palpebral raphe in the covering skin through 

 which it is seen, and which permits me to see the globe rolling in various directions. 

 The motores oculorum muscles are therefore developed to-day. 



Fore-arms and paws very strong. He gropes and pinches up the skin of his buttock 

 with his finger-nails, and seizes his tail, which he pulls with his hand. In the pouch 

 he held on to a handful of fur, which he grasped, in order the better to tug at the nipple. 



The tail highly prehensile. It wraps itself over the point of a pencil, and suspends him 

 in the air. He can suspend himself by the final twentieth of the organ. 



The mouth begins to assume a slit-like form; and is not so dimple-like as at first. 



The raphe of the lips extends far back. 



I put it in a cup of alcohol. It continued, during its immersion, to move freely and 

 strongly for sixteen minutes, by my watch, and then was apparently dead. 



I now adjusted and secured it on the back, for dissection. 



There was much fat beneath the skin, on the belly and thorax. (" Fat as a 'possum," 

 is an American saying.) 



When I opened the thorax I found the heart beating very evenly; and although I dis- 

 sected it nearly all the time, so as to remove the sides of the chest, and the abdominal 

 parictes, and opened the throat, and turned and fastened the tongue down with a needle 

 — the heart continued to pulsate until twenty-five minutes past eleven o'clock, one hour 

 and a half after its immersion in the alcohol. 



I take this fact as a proof of the powerful vitality of this creature. Such a fact was 

 not wanting to show the liberal endowment of its organic material with life force — 



