460 



ZOOLOGY 



SECT, 



The centrale of the carpus is sometimes absent. The dental 

 formula is the same as that of the preceding family. 



This family includes the Gibbons (Hylobates), Orangs (Simia) r 

 Chimpanzees (Anthropopithecus), and Gorillas (Gorilla). 



Family v. Hcminidce. 



Anthropoidea which differ from the Simiidae mainly in the more- 

 perfect assumption of the erect posture, co-ordinated with altera- 

 tion of the curvature of the spine, and with the more complete 

 adaptation of the hind-limbs to bearing the weight of the body, 

 in the absence of the power of opposition in the hallux, and its more 

 complete development in the pollex,in the greater length of the hind- 

 as compared with the fore-limbs, in the smaller size of the canine 

 teeth, and the much greater size and complexity of the brain. 



This family includes only the Human Species (Homo sapiens). 



Systematic Position of the Example. 



The genus Lepus, to which the common Rabbit belongs, com- 

 prises a number of other species, the common Hare being among 

 the number, distinguished from one another by slight differences- 

 in the proportions of the parts and other general features. Lepus 

 is the only genus of the family Leporidce, which is associated 

 with the family Lagomyidce or Picas under the designation Duplici- 



dentata owing to the pre- 

 sence in these two fami- 

 lies, and in these two- 

 alone, of the entire order 

 Rodentia to which they 

 belong, of a second pair of 

 jlf^fl \ Sf incisors in the upper jaw. 

 ra^is \ ' The chief distinctive 



features of the family 

 Leporidse are the elonga- 

 ted hind-limbs, the short 

 recurved tail, the long 

 ears, and the incomplete 

 clavicles. 



3. GENERAL ORGANIS&- 

 '/ TION. 



FIG. 1037. Section of human skin. Co, dermis; D, 

 sebaceous glands ; F, fat in dermis ; G, vessels in 

 dermis ; GP, vascular papillae ; H. hair ; N. nerves in 

 dermis ; NP. nervous papillae ; Se, horny layer of 

 epidermis; SD, sweat gland; SD', duct of sweat 

 gland ; 8M, Malpighian layer. (From Wiedersheim's 

 Comparative Anatomy.) 



Integument and 

 General External 

 Features. Nearly all 

 Mammals are covered 

 with hairs (Fig. 1037> 

 developed in hair-follicles. Each hair (Fig. 1038) is a slender 



