HISTOLOGY OF HIGHER ANIMALS 



55 



cytoplasm is granular. They are, however, dead, or at any rate 

 moribund cells. Owing to the constant friction to which the 



epd.< 



der. 



FIG. 18. Vertical Section of Stratified Epithelium from the Mouth of a 

 foetal Cat, X 280. (From a photograph.) 



der., dermis; epd., epidermis; s.m., Stratum Malpighii, or layer of actively dividing cells. 



surface of the body is exposed such cells are always being rubbed 

 off, and it is these which, by accumulating in places where the 

 friction is less severe, form the so-called scurf of the hair. 



FIG. 19. Section of Adipose Tissue from which the Fat has been dissolved 

 out, leaving the thin-walled Cells empty and shrivelled, X 175. (From 

 a photograph.) 



As they are worn away their places are taken by other cells 

 which arise from a deeply situated layer, at the lower limit of the 



