980 MR. R. I. POCOCK OX THE [Junel4, 



scanty in T. meminna* ; but I could detect no trace of any 

 secretion indicating special activit}' of the skin-glands of the 

 surfaces in question. 



In the Canielidae, as exemplified l>y Lama vicugna, the foot is 

 more specialised with respect to the extension of the web to a 

 point halfway between the heel and the nail of the hoof ; but the 

 anterior depression on the pastern is very deep and long and 

 glandular in its deeper portion, and the nail is small. (Text -fig. 



(Still more specialised is the foot in the (Suidte; for although 

 there is a dee2)er or shallower depression on the front of the 

 pastern, admitting of considerable distension of the hoof, the 

 anterior and posterior walls of the pastern are widely sepai'ated 

 and there is a strong deep interungual union extending forwaids 

 from the heels to a greater or less extent according to the 

 species. In a Peccary [Dicotyles collaris) the heels were separable 

 and the interungual union siiorter and the anterior depression 

 deeper than in a Wart-Hog (Phacoc/itefus), in which the depi-ession 

 was quite shallow and the interungual union long in comparison 

 (text-fig. 142, B, ])). In the foot of the Wart-Hog, moreovei-, 

 which was kindly given to me by llowland Ward, there was an actual 

 horny union between the heels, which were thus qviite in.'-eparable. 

 In lx»tli these species the interungual area was quite smooth ; 

 but I detected no trace of specialised glands t. 



lleverting once more to the liuminantia, I find, as is not sur- 

 prising, that the foot of the Musk-Deer(J/o6r/<»s) comes nearest to 

 that of y'ragaliis. The pastern-web of Moschus nearl}'' reaches 

 the heels of the hoofs but not quite ; the feet indeed, apart from 

 the wealth of hair that clothes them, are like those of Tragidas, 

 but very much shortened and having the glands of the depression 

 active. 



It is only a short stej) from the foot of Moschus to the hind 

 foot of Damo, or Klaphodas, the chief difierence being that in 

 these Deer the pastern- web extends right down to the heels, tying 



* 111 T. .s'faH/(7/o)(7(s also the skill of tlie buck of tlic pastern is coriacoous and 

 visible tlivoufjh the hairs, whirli are as scanty as on the inner surface of this part ; 

 whereas in T. meminna the skin is invisible on the back of the pastern when the 

 hairs are undisturbed. I have not invest igatc<l the subniandiiiular glands of 



t The secretion of the dorsal gland in both species of Peccary has a strong and 

 pungent odour, like concentrated hiinian perspiration. It may not be without 

 signiticaiice that the scent of theSontii American Tree Porcupines (CofHy/H villosus 

 u\ii\ prehensilis) is exactly the same, as I have alrejidy recorded (P. Z. S. 1908. p. 94G). 

 And since this scent has, I believe, a warning significance in the Porciii)ines, it may 

 be that we have here an instance of mimicry, Hatesian or Miillerian, in smell. On 

 till' other hand, the function of the gland in the Peccary may serve the jxirpose 

 merely of keeping the members of the herd together. Owen's figure and description 

 of this dor>al gland in the Peccary are not very satisfactory. He describes and 

 figures tiie gland as oiieniiig by an orifice in the mid-line of the back, without 

 mentioning any nipple ('Anatomy of Vertebrates,' iii. ]). i)3o, 18li8). PossilJy his 

 ])reparatioii was not made from fresh material, for in the specimens I have 

 examined the gland was niurkiKl externally by a conspicuous ujjstaiiding nipple. 

 This was traversed i)y a central duct dipping into the lobular fat-like tissue of the 

 gland. When the gland was squee/etl, fluid secretion could be easily made to exude 

 from the orifice at the summit of the nipple. (Text-fig. 142, C.) 



