1 62 THE ORIGIN OF THE NERVOUS SYSTEM 



involved. In the pyramidal cell of the cerebral cortex 

 (Fig. 46) the course of development according to Cajal 



Figs. 52, 53. — Neurons: Fig. 52, neuron from cephalic ganglion 

 of crab, Carcinus mamas (from Bethe, 1807); Fig. 53, neuron from 

 ventral cord of earthworm (from Retzius, 1892). 



(Fig. 54, A-E) is as follows: the primary outgrowth, 

 the axon arises on that side of the cell away from the 



