TISSUES OF SPECIAL FVXCTIOX. 



Ill 



divides into coarse extensions, which form a network of broad vari- 

 cose fibres, lying in a finely granular material containing two sorts 

 of nuclei. This whole structure lies in close relations to the con- 

 tractile substance of the muscle-fibre, but whether it is covered by 

 the sarcolemma or not is a matter of doubt. The nuclei in the 

 motor-plate are derived in part from the muscle-fibre, from the 

 cytoplasm of which the granular material surrounding the nerve- 



Fig.101. 



b c 



Motor-plate. Tail of a squirrel. (Galeotti and LeviJ a, two branches of axis-cylinder ter- 

 minating in a plexus of varicose filaments; b, muscle-nucleus; c, nucleus derived from 

 neurilemma. The finely granular substance surrounding these structures has been 

 omitted. 



endings appears to be derived, in part from cells similar to those 

 forming the neurilemma, which participate in the production of the 

 motor-plate (Figs. 101 and 102). 



Fig. 102. 



Granular bed 



of end organ L 



Nerve fib 



End arborisation 



Muscle fibre 





Motor nerve-endings in the fibres of a rat's abdominal muscle. In the upper fibre two end- 



plates are to be seen. 



The nerves of sensation, like those supplying the striated muscles, 

 end in bodies in which the nervous terminations are associated with 

 cellular structures of peculiar form. Their consideration will be 

 postponed until the structure of the nervous system is described. 



