BY DR. KLEIN. 99 



fifteen minutes. Thence they are transferred to a quarter per 

 cent, solution of nitrate of silver for thirty or sixty seconds, 

 and then exposed to the light until they acquire a brownish 

 color. They are further prepared in a drop of a mixture of 

 equal parts of ordinary acetic acid, glycerine, and water. In 

 such preparations a system of clear lines shows itself in the 

 striped brown ground of muscular substance. These lines 

 correspond exactly, in their whole arrangement, with the intra- 

 muscular nerves above described. 



Muscular Nerve Endings of Snakes and Lizards. 

 The most beautiful muscular nerve endings with which we are 

 acquainted are those of the reptilia, e.g., Lacerta agilis, Lacerta 

 mridiS) and Coluber natrix. In preparations of the muscle of 

 the thigh or of the back of the lizard in humor aqueus or 

 serum, it is seen that the medullated nerve fibres divide into 

 branches in the same way as in the frog. Here, as before, the 

 branches lose their medullary sheath just as they enter the 

 sarcolemma, and then resolve themselves into a beautiful digi- 

 tate or fringe-like expansion of pale fibres embedded in a 

 granular ground containing nuclei, resembling that described 

 in Hydrophilus, but of a laminar form. In the subcutaneous 

 muscles of Coluber natrix, the terminal expansion forms a rich 

 network of riband-shaped fibres embedded in a granular ground. 

 The network is so close that it looks like a lamina in which 

 round and oval orifices have been punched out. In silver 

 preparations made as above directed, as well in the lizard as 

 in the snake, the same facts may be demonstrated the intra- 

 muscular system of nerves exhibiting themselves as clear lines 

 on a brown ground. 



The endings of the muscular nerves of mammals resemble 

 those of reptiles. 



From the preceding details it appears that two forms of 

 muscular nerve endings may be distinguished. In the first 

 form, the ends of the axis-c3 T linder, or those of its branches, 

 lie in immediate contact with the muscular substance under- 

 neath the sarcolemma (frog). In the second, they are embed- 

 ded in a granulous gro-md (Hydropliilus, reptilia, mammalia). 

 The demonstration of nerve endings is one of the most difficult 

 tasks which can be undertaken by the histologist. 



