780 ANATOMY OF VERTEBRATES. 



depth, reminding one of the pair of marsupia in Echidna, save 

 that the milk escapes in front of, and not into, the pouches. 



418. In Caruivora. In the Seal-tribe, including the Walrus, 

 the number of teats does not exceed four. In the Otters 

 (Enhydra, Lutra) only two teats have been observed, ventral in 

 position. The Mustelida have from four to six ventral teats. 

 Six is the common number in Ursidce, two being pectoral and four 

 ventral. In Cercoleptes I found but two ventral teats. Procyon, 

 J\Icles, Taxidia, JVasua, have six ; Ailurus has eight teats. The 

 palm-cats (Paradoxurus) and Ichneumons (Herpestes} have four 

 ventral teats. They seem not to exceed that number in the Hyae- 

 nas ; but in the Civets two pectoral nipples are sometimes added to 

 the four ventral ones. The felines have usually six nipples, four 

 ventral, and two pectoral ; but in the domestic cat eight have 

 been seen. The Canidce, w r olf, dog, jackall, fox, have usually 

 eight teats. 



419. In Quadrumana. In the Aye-aye (Chiromys) there is 

 but one pair of nipples, situated about an inch and a half in ad- 

 vance of the vulva, and one inch apart: they are sub-elongate, 

 obtuse, with about a dozen terminal lacteal pores. To such a 

 pair of inguinal nipples some Lemuridce (Stenops, Tarsius, Micro- 

 cebus, e.g.) add a pectoral pair; while in Otolicnus and some 

 kinds of Maki (Lemur catta, e.g.) 1 two pairs of pectoral nipples 

 have been found. 



In platyrhine and catarhine Quadrumana the mammary glands 

 and nipples are restricted, as a rule, to a single pair, and 

 to the pectoral region. In the ordinary quadrupedal progres- 

 sion, the young, with its belly applied to that of the mother, 

 clings back downward, by the fore and hind feet to her flanks, 

 holding on by the mouth to the teat between her fore -legs. In 

 the seated posture the mother ape holds her young to the nipple 

 by the fore-limbs, in a very human fashion. The integument 

 covering the mammary gland is not protruded by its enlarge- 

 ment in the form of a hemispheroid f breast : ' it is covered with 

 hair, like the rest of the body, becomes conical and pendulous, 

 with much elongation of the nipple, as the suckling period is 

 prolonged. In an Orang-utan (Pithecus satyrus\ I have ob- 

 served an accessory nipple on the left side, below the normal 

 one and of smaller size. 2 From ten to twelve lacteal ducts open 

 upon the apex of the normal nipple in the Orang. Around the 

 base of the nipple open the orifices of sebaceous ducts. 



420. In Bimana the mammary glands, two in number, are 

 1 xx. vol. v. p. 208, no. 3775 A. - Ibid. B. 



