Volume II. December, l8g8. Number J. 



ZOOLOGICAL BULLETIN. 



NOTES ON THE FINER STRUCTURE OF THE 



NERVOUS SYSTEM OF CYNTHIA 



PARTITA (VERRILL). 



GEORGE WILLIAM HUNTER, Jr. 



In the fall of 1897, while working upon the morphology and 

 finer structure of the nervous system of Cynthia partita (Ver- 

 rill), after noting the papers of Von Lenhosseck ('95), Dehler 

 ('95), McClure ('96), and Miss Lewis ('96), I was led to look 

 for the centrosome and sphere in the cells of the central ner- 

 vous system. I was directly prompted to this investigation by 

 an examination of the plates of Van Benedcn and Julin's ('84) 

 early paper on the central nervous system of the Ascidians. 

 In PI. I, Figs. 2 and 3, these authors represent ganglion cells 

 with excentric invaginated nuclei. Careful study showed the 

 same thing to be true for the ganglion cells of Cynthia. I was, 

 however, not immediately successful in staining the centro- 

 some, although later material killed in more favorable reagents 

 showed that a structure homologous with the centrosome and 

 sphere of authors exists in the tunicate ganglion cell. The 

 incomplete notes on fibrillar structure of the nerve trunks are 

 given in view of the recent papers of Apathy ('97) and Bethe 

 ('98). It is hoped in a later paper to give a more complete 

 account of the cell structures and their relation to the neuron. 



Methods. 



Several fixing fluids were employed. They were found to 

 be of extremely varying utility as preservatives of the finer 

 structure of the central nervous system. The fluids of Flem- 



