STIMULATION AND WOKK. 169' 



change on the muscle fibres. This harmonizes mar- 

 vellously with Beale's theory of muscular action, 

 whereby fine nerves in closed circuits charged with 

 neuric force cross the fibres in contact with them but 

 outside the sarcolemma, instead of plunging into 

 living actively contractile matter and ending there as 

 Kiihne and the majority maintain. 



But with respect to the action of the vis nervosa as 

 a stimulus, according to Beale, we must admit two dis- 

 tinct modes, viz. ; 1st, that of the afferent and efferent 

 nerves in which a continuous closed circuit between* 

 the peripheral and the central protoplasm is formed, 

 and the nerve cords act by contact with the living^ 

 matter : in fact in what would correspond to electro- 

 lysis in chemical action, or neurolysis as we may say ; 

 and 2nd, by some induced or derived influence if a 

 stimulus is directly given to any other living matter 

 outside of the closed nerve circuit. This last mode also 

 seems to be now admitted by Dr. Beale.* We have 

 thus not the same simplicity as in the more common 



* In Dr. Beale's memoir on the relation of nerves and pigment, and 

 other cells [" M. Microsc. J." 3Teb. 1872], he re-asserts that whatever 

 be the nature of the influence produced by the nerves upon the struc- 

 ture and the action of various tissues and organs, it is not dependent 

 on continuity of substance between the nerve and the tissue aflected. 

 But he adds now that when contraction of bioplasm follows upon irrita- 

 tion of nerve fibres the result is due to a change in the nerve which 

 runs near to it, and not to an influence propagated to the bioplasm 

 from the nerve by reason of continuity of material. Though he here 

 denies that the nerve fibres are continuous with the connective tissue 

 corpuscles of the cornea, and with the pigment cells of fishes as main- 

 tained respectively by Kiihne and Pouchet, yet this is an admission of 

 the vital action of nerve force on protoplasm as a stimulus and is an 

 abandonment of his previous position, and allows the whole doctrine- 

 of trophic and secreting nerve influence. For be it observed, it is hera 

 a vital act under nerve stimulation that is in question not the physi- 

 cal contraction of a muscular fibre which is always pronounced to be- 

 dead. 



