20 CLASS MAMMALIA. 



pouch, in such species as have this appendage. There is 

 nothing remarkable in the mammae of those which are 

 without this organ, or have only a lateral fold. In the 

 anomalous species, it is generally asserted that there are 

 none, and the assertion may, perhaps, be true. 



The male sex, in the marsupial animals, presents some 

 singularities worthy attention, though in the disposition of 

 its general structure it agrees with the other Mammalia. We 

 can only venture, however, to hint at them, as they are not 

 of a nature fit for any detailed description, and can be 

 instructive or amusing only to professional readers. There 

 is no trace of a pouch in the male Marsupiata, nor probably 

 of mammas. 



M. De Blainville is inclined to disbelieve the existence of 

 the placenta. He also thinks that the foetus in the anoma- 

 lous species arrives to more perfection in the uterus than 

 among the other tribes. 



As to the mode in which the young are placed in the 

 external pouch, or rather attached to the nipple, M. De 

 Blainville leaves it in doubt. A communication between 

 the external uterus and this pouch has been asserted to 

 exist, but never demonstrated. Some have imagined that 

 the mother placed the young there herself with her hands 

 and feet ; but this is not very likely. Another opinion (which 

 we noticed before) was, that the pouch extended to the 

 orifice of the vagina; but the muscles do not seem dis- 

 posed for such an arrangement, and some species have no 

 pouch. Certainly nothing is accurately known on this 

 subject, though we think that the conjecture of M. GeofFroy, 

 before cited, is the most probable. 



We shall conclude this article with a few more general 

 observations relative to the nomenclature, divisions, and 

 habits of these curious animals, and such other peculiarities 

 as may have been unnoticed. 



These animals (as we have observed) derive their appel- 



