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



membrane which covers it; the latter being considerably 

 smaller and flatter, rarely exhibiting a distinct nucleolus, and 

 being always finely punctated or granular. As Krause has 

 shown, they lie in the membrane, and may be regarded as the 

 nuclei of the sheath of Schwann, where the latter, expanded 

 over the eminence, is about to pass into the sarcolemma. 



Nuclei presenting these characters are consequently only 

 found upon the upper part of the eminence, so that their position 

 alone renders it impossible to mistake them for the vesicular 

 nuclei which are present only at the base of the eminence, or 

 that portion of it which is directed towards the muscle. The 

 small, hazy nuclei are distributed in far smaller number and 

 irregularly in the membrane of the eminence, whilst the vesi- 

 cular nuclei are arranged more or less definitely around the 

 margin of the base. Finally, these small ellipsoids are placed 

 with their long axis radially to the axis of the muscular fibre. 

 They vary but slightly in size ; in the lizards they are very 

 little larger than the muscle nuclei, from which they are dis- 

 tinguished by their somewhat less elongated form, and by their 

 presenting more rarely two nucleoli in their interior. In the 

 warm-blooded animals, on the other hand, their size con- 

 siderably exceeds that of the muscle nuclei. 



The form of the nerve eminence in the muscles of Keptilia 

 presents all conceivable varieties, being sometimes higher, and 

 sometimes lower ; sometimes having a long, elliptical, or even 

 very extended basis ; at others being nearly circular, or pre- 

 senting the shape of a parallelogram with rounded angles. 

 Those that are the most elongated are always the least promi- 

 nent, forming, when the nerve end is seen in profile, scarcely 

 any projection from the muscular fibre. In the warm-blooded 

 animals, in which the nerve eminence is nearly circular, the 

 eminence is likewise very flat, relations which are here only 

 alluded to, since they appear to be of subordinate importance. 



The muscles of warm-blooded animals, as is well known, alter 

 with great rapidity after death, and it is not surprising, there- 

 fore, that organs so delicate as the extremities of the nerves 

 should likewise undergo cadaveric changes. Researches on 

 the minute anatomy of these parts ought therefore to be com- 

 menced on Reptiles, whose muscles, especially at a low tempera- 



