TEKMINATION OF MOTOR NERVES IN VERTEBRATA. 219 



ture, remain, like those of Amphibia, excitable for an astonish- 

 ingly long period. It is, in truth, not difficult to recognise in 

 lizards, as in Lacerta agilis and L. viridis, the mode in which the 

 nerve terminates in the Doyerian eminence. The granular mass, 

 together with its nuclei, forms only the base or floor of the 

 nerve end, whilst this is itself composed of a transparent non- 

 granular plate, the terminal nerve plate,or the motor nerve plate. 

 At whatever period after death the muscles may be examined 



A. 



Fig. 36. 

 B. 



Fig. 36. Muscular fibres with nerve ends, from Lacerta viridis. 



A. Seen in profile ; pp, the terminal nerve plate ; s s, the base or sup- 

 port of the plate, consisting of a granular mass with nuclei. 



B. The same as seen in a perfectly fresh muscular fibre, whose nerve 

 ends are still probably excitable ; the delicate and pale contours which 

 the frequently branched plate naturally possesses are not expressed in 

 the woodcut. 



c. The same as it appears after the death of the nerve end, as, for 

 instance, two hours after poisoning with large doses of woorara. 



there will always be found a third element in addition to those 

 above named; namely, vesicles of various form, which are clear 

 and transparent, pale contoured, and free from nucleoli; and 

 these are to be found also in the nerve eminences of the 

 warm-blooded animals. They are products of the very easily 

 alterable nerve plate, probably acted on by the post-mortem 

 formation of acid in the muscle. 



Completely isolated muscular fibres removed from the still 

 irritable thigh of a lizard, show characters which are almost 



s 



