HENCHMAN, ^Nervous System of Litnaz. 



PLATE I. 



All the figures of this plate were made from material killed in Perenyi's fluid, and 

 all except Fig. 1 are magnified 250 diameters. 



Fig. 1. A small portion of Fig. 5 more highly magnified to show the cell prolifer- 

 ation for the right pedal ganglion. 



" 2. Posterior face of a transverse section from an individual about six days 

 old. The section passes anterior to the "pleural groove," and through 

 the region where the cerebral invaginations subsequently arise; the 

 left side is cut a little anterior to the right. Stained in alcoholic 

 borax-carmine. 



" 3. A section from the same individual posterior to the pleural groove in the 

 region of the cell proliferation for the pedal ganglia. 



" 4. A section from the same, still farther back. 



" 5. Transverse section from an embryo a few hours older than the preceding, 

 in the region of the proliferation to form the pedal ganglion. Stained 

 in alcoholic borax-carmine. 



" 6-9. The left surface of sections parallel to the sagittal plane from an em- 

 bryo of the seventh day. Figs. 6, 8, and 9 represent respectively the 

 11th, 16th, and 18tli sections of the series, and are from the left half 

 of the embryo. Fig. 7 is from the right half, and passes through 

 the right otocyst. Stained in Czoker's cochineal. 



" 10-13 exhibit the riglit surface of sections from another individual (between the 

 seventh and eighth days) cut parallel to the sagittal plane, the anterior 

 portion a little in advance of the posterior. Fig. 10 is a section passing 

 through the proliferation forming the right visceral ganglion. Figs 11 

 and 12 are two successive sections passing through the left visceral 

 ganglion ; the latter also passes through the left otocyst. Fig. lo 

 shows the region of the forming abdominal ganglion. Stained in picro- 

 carminate of lithium. In both these individuals the left ganglia and 

 otocysts are more developed than the right. 



