240 PHYSIOLOGY OF Mrsri.KS AM> NKIJVES. 



what differ* >nt ; hut tin- relation between the nerve and 

 the muscle is the same. The essential fact is the same 

 in all cases: ////>, m-rre _/"'-'*'* ''"/" direct contact 

 n-ltli tlf muscle-substance. All observers are now 

 a -Teed on this point. Uncertainty prevails only as to 

 the further )iature of the terminal plate. In the frog, 

 for instance, there is no real terminal plate, but the 

 nerve separates within the sarcoleinma into a net-like 

 series of branches, which can be traced for a short dis- 

 tance from the point of entrance in both directions. 

 Professor Gerlach has recently declared that this net, 

 as well as the terminal nerve-plate, are not really the 

 ends of the nerves, but that the nerve penetrates 

 throughout the muscle-substance, and that throughout 

 the whole muscle-fibre there is an intimate union of 

 nerve and muscle. 



2. However -this may be, the fact that the nerve- 

 substance and the muscle-substance are in immediate 

 contact must serve as the starting-point from which to 

 attempt an explanation. "When it was thought that 

 the nerve remained on the outer surface of the muscle- 

 fibre, there was difficulty in explaining how a pulsation 

 of individual muscle-fibres within a muscle could bo 

 elicited by irritation of individual fibres of a nerve. 

 Kor the nerve-fibres, in their course within the nm-< le. 

 touch externally many muscle-fibres, over which they 

 pass before they finally end at another mnsde-liltre. 

 In the case of flat, thin muscles, it may be shown con- 

 clusively that such a nerve-fibre may be irritated in 

 such a way that those muscle-fibres over which it, 

 passes remain quiescent, and only those pulsate at 

 which the nerve-fibre ends. As soon, however, as it is 

 understood that the excite nt present in tl e nerve- 



