Sargent, Giant Ganglion Cells of Ctenolabfus. 183 



The Giant Ganglion Cells in the Spinal Cord of Cten- 



OLABRUS AUSPERSUS (WaLB.-GoODE). 



By Porter E. Sargent, 



Harvard University. 



During the winter of '97- g^ while engaged in the study 

 of Golgi preparations of the central nervous system of the 

 common cunner, Ctenolabrus adspersus, my attention was at- 

 tracted to large bodies lying in the median dorsal fissure of the 

 spinal cord. A little study showed them to be nerve cells of 

 gigantic proportions, giving off a ventral process. 



The following preliminary paper is a summary of studies 

 made during the spring of 1898. No attempt at a critical dis- 

 cussion of the subject will be attempted in this paper, that be- 

 ing reserved for the final article. 1 wish here to express my ob- 

 ligations to Prof E. L. Mark for kindly advice and assistance, 

 and to Mr. Alexander Agassiz for opportunities enjoyed at his 

 Newport Laboratory, where ihe material for this study was 

 collected and prepared. 



Colossal ganglion cells in the spinal cord of certain Ichthy- 

 opsida have attracted the attention of a large number of obser- 

 vers during the past forty years. Upward of sixty articles in 

 the literature deal with the subject to a greater or less extent. 

 The greater number of these papers have to do with a transient 

 nervous apparatus existing only in the embryos and larval 

 stages. The most recent papers on this subject are those of 

 Studnicka '95 and Beard '96. 



In adult fishes giant ganglion cells occurring in the dorsal 

 portion of the cord have been noted by many investigators from 

 Miiller '44 to Kolster '98. Most of these observations are frag- 

 mentary and all are very incomplete, so that as yet little is 

 known of the occurrence, distribution and stucture of these 

 cells, and almost nothing of the course of their fibers, while 

 their function is a mere matter of conjecture. In only one in- 

 stance have the neurites been traced. Fritsch '84 and '86 found 

 that the giant cells imbedded in the anterior part of the cord of 



