324 Prof. Owen on the Reproduction of the Opossum. 



XXX. — Note on Dr. Meigs's Memoir on the Reproduction of the 

 Opossum. By Prof. Owen, F.R.S. 



To the Editors of the Annals of Natural History. 



Gentlemen, 

 I have been favoured by Mr. Everett, the late highly-respected 

 Minister of the United States in this country, with the following 

 extract from the Proceedings of the ( American Philosophical So- 

 ciety * for April 16th, 1847 ; which, as it contributes to elucidate 

 one of the most singular subjects in the animal oeconomy, will no 

 doubt be acceptable to your readers: — 



•' The Committee (Drs. I^ays, Bache and Condie), to whom had 

 been referred the memoir of Dr. Charles D. Meigs, upon the repro- 

 duction of Didelphys virginiana, read 19th March 1847, reported, 

 recommending its publication in the Transactions of the Society, 

 which was ordered accordingly. 



" Professor Owen's paper on the reproduction of the Kangaroo and 

 the Wombat has left certain points still unsettled as to the repro- 

 duction of the marsupials ; and MM. Milne Edwards and Pouchet, 

 in their works, have left uncleared several points, which it is the 

 object of Dr. M.'s paper to explain. 



" The terms foetus and embryo cannot properly be applied to the 

 young of the Didelphys while in the pouch ; since, when first placed 

 in the marsupium, the young opossum is endowed with all the attri- 

 butes of a mammiferous quadruped in the full enjoyment of a real 

 warm-blooded respiratory and digestive existence. None of the au- 

 thors on this subject appear to have investigated the state of the early 

 young ; and the most vague and incorrect notions still prevail as to 

 their condition. 



" On the 18th of February 1847, a light snow having fallen, the 

 tracks of two opossums were followed on the 19th over the snow to 

 the trunk of a hollow tree, wherein they had concealed themselves, 

 and from which were taken a full-grown male and female Didelphys. 

 It was supposed, from the appearance of the testes in the male, and 

 the monotrem of the female, that the animals had retired for the rut, 

 Us they are rarely found in company at other seasons. 



" On the 27 th February they were brought to me, and I carefully 

 examined the marsupium, but could discover no trace of any mam- 

 mary development of the base of the delicate nipples. February 

 28th, no change was discovered by inspection or careful palpation 

 of the pouch. On Monday, March 1st, and on Tuesday the 2nd, 

 there was not the least sign of change in the pouch. On Wednesday 

 the 3rd, the mammary glands were visibly and palpably enlarged. 

 On Thursday, 4th, still larger. On Friday, 5th, hard and swollen. 

 Saturday, 6th, passed without my inspection ; but my servant ex- 

 amined the pouch and discovered no young ones at the teats. At 

 3 p.m. on Sunday, 7th March, I opened the pouch, and discovered the 

 young animals adhering to the nipples. 



" Here then was a manifest preparation for the reception of the 



