INTEGUMENTARY SYSTEM 



97 



hairs are naturally more noticeable the more the individual 

 inclines towards the brunette type. 



This fact justifies our including man among the hairy 

 animals, especially when considered in conjunction with certain 

 phases of his embryonic development. In the seventh month 

 of intra-uterine life, the human foetus is covered with a coat 

 of fine, downy hair, which, on the authority of Eschricht, is 

 arranged in crests and circles that determine its direction. The 

 hair is then most thickly developed in the region of the ischial 

 tuberosities, while the palms of the hands and the soles of the 



-r^" ~1 rr~ ___ -^-^~~.^-lL-^ ~~ ^=^.rfte 



FIG. 49. Section of skin of finger tip. (Magnified twenty times). (Thome, Zool- 

 ogie.) i, Epidermis; *, Lowest layer of same; 2, Basement membrane; 

 3, Papillae ; 4, Corium ; 5, Adipose membrane ; 6-6 Sweat ducts (pores of 

 the skin) ; 7, Sweat glands ; 8, Section of a vein. 



feet, the red part of the lips and the glans penis and clitoridis 

 are quite bare. 



This first coat of hair eventually disappears, and makes way 

 for a new permanent one acquired during the first few years of 

 life, the hairs of which gradually increase in size and become 

 deeper in colour. Thus arises, besides the pale-coloured downy 

 hairs, the darker hair of the head, eyebrows and eyelashes. 

 On the approach of puberty the axillary hair and pubes are 

 developed, these being peculiar to man and possessed by no 

 other mammal,, and as full maturity is reached the growth of 

 hair increases on the chest, back and extremities in the male 



7 



