172 Journal of Entomologj and Zoology 



alcohol, sections were cut in paraffine. Some sections were stained 

 with iron hematoxylin, but some were mounted unstained and occa- 

 sionally a very fine Golgi-like impregnation of certain cells with 

 their branches was evident. From such preparations it was learned 

 that the cell processes were about one to a cell and that this often 

 branched at halt its length or a little more, although it was difficult 

 to make this out because ot frequent crossing of the fibers. Most 

 cells seemed to be uni- or bi-polar, but some had other branches 

 running back among the cells oi the celular area. In some places 

 the long fibers from the cells were very wavy and they often ran 

 slantingly, crossing main cell processes, some may have been larger 

 than others, although it was impossible to be sure oi their compara- 

 tive size because oi differences in position and staining. In small 

 specimens smaller fibers or fibrils were evident and very numerous. 

 In this, as compared with the starfish studied, there was more the 

 indication of fibrillae, but no marked development oi these. ( )n the 

 whole, the central nervous system seems more like the complex sys- 

 tems ot other forms than does starfish. 



1 he nerve cells are well marked, sometimes with nucleoli and 

 with much chromatin but not usually with the characteristic arrange- 

 ment of chromatin material. In some cases a small amount oi 

 material in the cytoplasm gave the appearance oi tigroid substance. 

 As in starfish, fibers from cells usually appeared as single fibrils 

 especially in the adult. In main places the fibers or fibrils seemed 

 to start rather abruptly from the outer /one oi cytoplasm oi its cell. 

 In a tew cases two fibers seemed to start from the same place in a 

 cell, but this ot course may have been where one ot the fibers in 

 crossing was cut off, or possibly fibers entering and leaving the 

 same cell. The details ot fibers and cells were taken from Flem- 

 ming's fluid preparations either stained or unstained. 



I he segmental arrangement of ganglia in the arms is one ot the 

 well known features which forms such a striking resemblance to 

 the ganglionic cords ot many segmented animals. In some ot the 

 smaller specimens the condition ot the gangila is especially well 

 marked, towards the ends the nerve strand becomes quite reduced. 

 In longitudinal sections ot the arms ot serpent stars the thicker cell 

 area is. o\ course, that ol the superficial radial nerve while the cells 



