224 



derived from the study of many preparations indicates, however, that 

 this branch (Fig. 3, a) turns laterad and dorsad and after branching 

 repeatedly becomes lost in the network of the dorsal horn of the gray 

 substance. 



Summary. 



In the anterior third of the spinal cord of Ctenolabrus cceruleus 

 there is a series of from 35 to 40 giant ganglion cells lying in the 

 dorsal fissure, each cell enveloped in a capsule. 



The anterior end of this series occupies the posterior edge of the 

 fissura rhomboidalis, where there are two pairs of symmetrically placed 

 giant cells lying on the surface of the cord, two cells on either side of 

 the canalis centralis. 



The form of the cells is variable. Numerous dendrites are given 

 off, which anastomose with the surrounding neuroglia cells and some- 

 times with the dendrites of other giant cells. 



The cytoplasm contains elongated granules arranged concentrically 

 with the wall of the cell. 



Each cell gives off an axis cylinder which runs ventrad and lat- 

 erad, usually dividing iuto two equal neuntes, one of which enters 

 the lateral fibre bundle. 



The neuntes follow this fibre bundle through the cord either 

 cephalad or caudad. 



The fibre bundle running forward through the cord and medulla 

 passes out through the ventral root of the trigeminus nerve. 



The other branch apparently divides and becomes lost in the net- 

 work of the dorsal horn. 



Preliminary observations have been made on the occurrence of 

 giant ganglion cells in other species of Teleosts, in which they have 

 not previously been recorded. In the trout 3 cm long giant cells occur 

 in or near the dorsal fissure. They are so conspicuous in cross sections 

 of the cord that it seems strange that Kohon ('85) and Van Ge- 

 huchten ('97) failed to find them. They were also found in the 

 sculpin, cod, eel, and yellow flounder. In Motella, Atherina, Fundulus 

 and the stickleback I failed to find them. In my final paper I hope 

 to treat this subject in a comparative way. 



Cambridge, Mass., U.S.A. (Eingegangen am 6. November.) 



July 25, 1898. 



