202 Journal of Comparative Neurology. 



Notes on the Peripheral Nervous System of Molgula 

 manhattensis. 



By G. W. Hunter, Jr. 



These observations were made during the summer of 1897, 

 at the Marine Biological Laboratory. The forms used were 

 Molgula manhattensis and Cy nt J lia partita (Verrill). The former 

 was the more productive of results owing the ease with which it 

 could be freed from its tunic. Young specimens, on account 

 of the clearness of their tissues, could be used as whole mounts. 



Two methods were used for the staining of the peripheral 

 system. Molgulae were immersed in a weak solution of methy- 

 lene blue (i-iooo) for I ^ to 2j4 hours and left in running 

 water a few moments before dissection. A slight exposure to 

 the air seemed favorable to the stain. Injection of a strong so- 

 lution of (B. X. Meyer) methylene blue (i to 4^) also gave very 

 favorable results. In the latter case the blue was injected into 

 the ovarian vein, from whence it reached the heart and was dis- 

 tributed over the body. After one hour specimens thus in- 

 jected frequently showed the whole peripheral system sharply 

 defined. 



(i). Sensory cells in the endostyle. 



The endosyle in Molgula resembles that organ in the other 

 Tunicates. At the bottom of the endostylar groove is found a 

 row of flagellated cells, next come two laterally placed pads of 

 gland cells, each pad divided by a row of deeply stained, closely 

 packed spindle cells, the nuclei of which lie at different levels. 

 These cells possess very short spike-like cilia and stain deeply 

 with haematoxylin. Outside the glandular epithelium are found 

 ciliated cells ; the whole apparatus being bordered with a lip 

 lined with cubical ciliated epithelium, which seems to be contin- 

 uous with that of the peri-pharyngeal bands. 



The sensory cells are found in the lateral position occupied 

 by the above mentioned deeply staining spindle shaped cells. 

 These cells are quite numerous, sometimes several hundred ap- 



