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JOURNAL OF ENTOMOLOGY AND ZOOLOGY 



sides and also dorsally. The groups of larger cells were often 

 surrounded by many others, both of the neuroglia type and of 

 the smaller nerve cell form. In the largest neurones, as in the 

 smaller ones, the nuclei are prominent with marked nucleoli 

 which have one or more dark areas in tlieuL Surrounding the 

 nucleus there is a tine meshwork or cell reticulum upon which 

 granules of tigroid substance may be seen. This material is 

 in the form of fine granules in some cells, in others it is com- 



Figiire 1. Cells from tlie central nervous system of spiders, X800. A to E, cells 

 from tarantula; D and E, supporting cells; F", nerve cell from a spider 

 IJ/j mm. long; G, nerve cell or neuroblast from a young spider 

 of about ly^ mm. length. 



posed of coarser flakes. Eunning through the meshwork of the 

 cell with its tigroid substance delicate continuous strands or 

 neuro-tibrilla? may be seen and traced from the region of the 

 nucleus into branches of the nerve cell. Adjacent cells may be 

 seen to be in some communication with each other by means of 

 these tine tibrillfe. Broader connections between cells such as 

 Haller '04 and Hilton '11 have recorded in insects seem to 

 occur in this form to a limited degree (Fig. 1, A and B). 



