NERVE FIBRES AND NERVES 



819 



centre, they branch and send their ultimate twigs among the cells, without, how- 

 ever, uniting with them. f 



Termination. Axones terminate peripherally in various ways and may be most 

 conveniently studied in the efferent and afferent systems respectively. The 

 so-called peripheral terminations of afferent neurones are better called peripheral 

 nerve beginnings, on account of their functional relations; the impulse is excited 

 in the peripheral end and conducted centrad through the rest of the neurone. 



D 



FIG. 590. Showing some varieties of peripheral terminations of afferent neurones (or "peripheral nerve 

 beginnings"): 'A. Terminal fibriHa* in epithelium (after Retzius). B. Tactile corpuscle (Meissner's, after 

 Dogiel). C. Bulboid corpuscle (Krause's, after Dogiel). D. Lamellated corpuscle (Pacini's, after Dogiel, Sala, 

 and others). E. Genital nerve corpuscle from human glans penis (after Dogiel). a. Axone. t. Telodendria. 



Modes of Termination of Axones. The ultimate terminals of the axones and their 

 collaterals are called telodendrions (or telodendria). So far as can be determined 

 by present methods they invariably end " free," commonly by exhaustion through 

 multiple division. This manifold branching presumably puts the neurone in a 

 condition to influence the processes of many other neurones ("avalanche con- 

 duction" of Ramon y Cajal). In some localities the formation by axonic terminals 

 of pericellular and peridendritic networks has been observed. Upon muscle 



