THE FROG : HISTOLOGY, GERM CELLS, DEATH 93 



cell or neuron there may be distinguished (1) a cell body, 

 containing the nucleus, (2) a long process 

 known as the axon, along which impulses 

 are discharged, (3) 1 other processes, usually 



pig. cap. 



Nervous 



Tissue. 



e r. 



Fig. 52. — A section of the skin of a frog, taken vertically to the 

 surface, highly magnified. 



&.v., Small blood vessels; cap., capillaries; d.L, dense layer of connective tissue, 

 consisting of fibres which lie parallel to the surface ; der. t dermis or corium ; ep., 

 epidermis ; gZ'., gi"., g?"-, glands of three kinds; gl '. andg?'. secrete a slimy 

 mucus and pass it to the surface of the skin by ducts which are not shown in the 

 section ; gt". secretes a more watery secretion which probably contains a 

 substance of unpleasant taste ; all three kinds are simple glands of the saccular 

 type; k.l., horny layer of the epidermis; M.L, lowest row of the Malpighian 

 layer of the epidermis ; pig. , pigment cells ; v.f. , strands of vertical fibres in the 

 connective tissue. 



short, numerous, and highly branched, known as the 

 dendrites, along which impulses reach the cell The 

 axon ends by breaking up into a tuft of branches, the 



