86 Journal op Comparative Neurology. 



These observations pertain to preparations made of sympa- 

 thetic ^ ganglia of the following vertebrates : — 



Fishes, — black and rock bass and perch, {Microptcrous 

 dolomicn [Raf.], Amb lop lite s rupcstris [Raf.], Perca flavescais 

 [Mitch.]). 



Amphibia, — frog, {Rana catcsbimia and Rana halecurd). 



Reptilia, — tortoise, {Chryscniys picta, CJielhydra serpentina, 

 Emys ntcleagaris). 



Birds, — chicken, Gallus doniesticns. 



Mammalia, — Guinea pig, rabbit, cat and dog. 



Structure of the cell bodies of ?ieurons of the sympathetic sys- 

 tem. — The structure of the cell body of nerve cells of the sym- 

 pathetic system does not differ in any essential from that of mo- 

 tor or sensory neurons. 



In sympathetic ganglia stained in methylen-blue, fixed in 

 ammonia molybdate and sectioned, only a few of the cells in 

 any one section are as a rule stained ; some deeply, others with 

 varying degrees of intensity, while many of the cells are en- 

 tirely unstained. This enables the observer to study the devel- 

 opment of the staining in the ganglion cells. Under high power 

 it may readily be seen that the staining of the cell bodies is due to 

 the fact that certain granules — cJiromophile gratmles — which show 

 an especial affinity for the stain, give them their color. Chro- 

 mophile granules rn the cell bodies of neurons were first de- 

 scribed by Nissl, who has further shown that in pathological 

 conditions involving nerve cells, these granules are markedly 

 affected. In the motor cells of the cord these granules are rela- 

 tively large, giving the cell a mottled appearance. In sensory 

 cells (spinal ganglia) they are often quite small (Lenhossek). In 

 sympathetic nerve cells, where faintly stained, only a few very 

 small chromophile granules are to be seen scattered more or less 

 evenly through the protoplasm ; while in more deeply stained 

 cells the granules are more closely packed, are usually some- 

 what larger, and have often an angular shape. Between the 



' The results here briefly referred to will appear in a much fuller account 

 accompanying colored plates, now in preparation. 



