222 MODE OF TERMINATION OF MOTOR NERVES, BY W. KUHNE. 



changes of the terminal plate of the nerve depend on the post- 

 mortem, acidification of the muscle. 



What has been already stated in reference to the muscles of 

 Lizards and Snakes is equally applicable to those of warm-blooded 

 animals, and also to those of Man. It is, indeed, scarcely pos- 

 sible to break up human muscles under the microscope in so 

 fresh a condition that they may still be excited by irritation of 

 their nerves, but they may be obtained so well preserved from 

 amputated limbs that the terminal plate can be demonstrated 

 with its nerve eminence but little altered, or, at all events, not 

 separated into distinct masses by a process of constriction. The 

 plates can be immediately seen in the muscles of Mammals and 

 Birds, only these should be prevented from becoming too rapidly 

 stiffened; and this may easily be accomplished by lowering the 

 temperature of the preparation to 32 Fahr., and the addition of 

 serum at the same temperature on cooled slides. With the rigidity 

 which here always supervenes on the tetanic condition, the 

 object ceases to be available for investigation, chiefly on account 

 of the deeper-lying fibres of the muscle becoming too opaque ; 

 and as the terminations of the motor nerves in these animals 

 become paralysed instantaneously after the cessation of the cir- 

 culation of the blood through them, it follows that, even in the 

 freshest condition of preparations taken from warm-blooded 

 animals, the plates do not present very sharp outlines. 



The determination of the thickness of the terminal plate 

 and its relations to the adjoining parts, are points that demand 

 methodical investigation. In the small nerve eminences of 

 slender muscular fibres it presents itself when examined in 

 profile as a thin mass projecting externally into the medullated 

 nerve fibre somewhat in the form of a cone, with a sinuous 

 inferior border, which is turned twards the basal substance or 

 matrix on which it rests throughout its whole extent, and by 

 which, as by a layer equal to itself in thickness, it is separated 

 from the contractile substance. In accurately made transverse 

 sections of the frozen muscles of Lizards, it appears, on the 

 other hand, in the form of an irregularly reniform mass which, 

 at some points at least, gives the impression of being directly 

 superimposed upon the muscular prisms. Such preparations 

 remove every doubt respecting the relative position of the 



