CONGENERS. 339 



deer was taken on board. On the question of the habitat of these 

 animals, I have deemed it important to be very particular, and 

 the result is that I cannot doubt that their nativities are as 

 stated. 



Had both been found in the same range, I confess I should 

 have long hesitated before concluding that the absence of the 

 metatarsal gland in one, and its presence in the other, would 

 alone justify us in declaring a specific difference; nor would it in 

 any case, but from the fact that an examination of a great num- 

 ber of individuals of most of the species, and a considerable num- 

 ber of all, enable us to say that it is the most constant and uni- 

 form of all the indicia to be found on any of them. Where it is 

 wanting on one individual of a species, it is wanting on all, and 

 where it is present on one, it is present on all, and is precisely 

 alike on all of the same species, and entirely unlike that found on 

 either of the other species ; so that no two of different species at 

 all resemble each other in this regard, while in no two of the same 

 species can any difference be detected. If other naturalists have 

 attached less importance, or even no importance, to this than I 

 do, I must be pardoned for saying that I think it is because they 

 have studied it less. 



Had I found this gland present or absent in both, and so been 

 unable to point out any substantial difference between them 

 although coming from so widely separated localities, what should 

 I say then as to their specific identity ; when it is certain that 

 the races must have been separated for an immense period of 

 time, to say the least? He who will answer the following ques- 

 tion will answer that. When races or animals are alike, but in 

 nowise related to each other, are they of the same species ? In 

 connection with this subject, I repeat, that under the most fav- 

 orable circumstances I found these deer to interbreed very reluc- 

 tantly, and months after the proper season, but then the union 

 was fully fertile, for the doe produced twins; however, these 

 were still-born, or died very soon after birth. Not the least indi- 

 cation of the metatarsal gland can be found on either of these 

 fawns, which, of course, are added to my collection. I do not 

 know but hybrids are as liable to be twins as others. Mares 

 very rarely have twins, and yet I have heard of one well au- 

 thenticated instance of twin mules in my own neighborhood. 



Altogether I think it very clear that there is a sexual aversion 

 observed in these deer which is usually observed between individ- 

 uals of different species, which augments the evidence of specific 



