392 JOHNS HOPKINS UNIVERSITY MORPHOLOGICAL MONOGRAPHS. 



Figures 11-12, transverse sections of the ventral portion of the same ganglion 

 shown in Fig. 10. Fig. 12 represents the more anterior section. The disk-shaped 

 gland is shown at h, and one of the ventro-lateral outgrowths from the ganglion at b. 

 X 1 80 diameters. 



PLATE XLIX. 

 CYCLOSALPA PINNATA, Chain Form, Adult. 



Figures 1 and 2, longitudinal, vertical sections of the ganglion and unpaired eye. 

 Fig. 2 represents the section nearer the mid-line. The three regions of the unpaired 

 . eye are shown, e', e", e'". X 157 diameters. 



Figure 3, part of a horizontal section through the region marked e' in Fig. 2. It 

 shows the thick-walled ends of the rod cells in cross-section. The nucleus-like bodies 

 (secondary nuclei) should be more homogeneous. 



Figure 4, a transverse section of the ganglion through the region marked on in 

 Fig. 1. X 157 diameters. 



Figure 5, a more anterior section from the same series, cutting the eye through 

 the region marked e' in Fig. 2. X 157 diameters. 



Figure 0, a more enlarged drawing of the right limb of the eye shown in Fig. 4. 

 X 278 diameters. 



Figure 7, an optical section of a piece of the second, smaller portion of the 

 unpaired eye, separated by teasing and having some of the fibers of the optic nerve 

 still attached. X 157 diameters. 



Figure 8, a longitudinal, vertical section of the antero-dorsal half of the ganglion, 

 showing one of each pair of smaller eyes, ex, eij. The position of the large unpaired 

 eye, e', is indicated. X 481 diameters. 



Figure 9, the nerve plexus on the dorsal surface of the ciliated funnel. X 265 

 diameters. 



PLATE L. 



SUBNEURAL GLAND OF CYCLOSALPA PlNNATA, Chain Form. 



Figure 1, a longitudinal, vertical section of the ganglion at a stage of develop- 

 ment corresponding to that represented in Plate XLVII, Fig. 2, showing the com- 

 mencement of the formation of the lateral tubes of the subneural gland, h. The 

 section is on one side of the middle line, x 240 diameters. 



Figure 2, an oblique section of the ganglion at the same stage of development as 

 that shown in Fig. 1, showing part of the remnant of the duct from the ganglion to 

 the ciliated funnel, v. X 240 diameters. 



Figure 3, a longitudinal section of the ganglion at a stage of development cor- 

 responding to Figs. 5 and 6, Plate XLVII, showing a later stage in the formation of 

 the lateral tubes of the subneural gland. X 240 diameters. 



Figures 4-6, longitudinal sections, not quite vertical, of the adult ganglion and 

 the adjacent parts, showing the subneural gland, d and h, and the ventro-lateral 

 outgrowths from the ganglion, b and b'. Fig. 4 is nearer the mid-line. X 157 

 diameters. 



Figure 7, a longitudinal section of the disk-like enlargement of the neural end of 

 one of the lateral tubes. X 408 diameters. 



Figures 8-11, transverse sections of the ventral half of the ganglion and the adja- 

 cent parts, showing the relation of the subneural gland to the ventro-lateral out- 

 growths from the ganglion. Fig. 11 is the more anterior. X 157 diameters. 



Figure 12, two cells from the large-celled ventro-lateral outgrowth from the 

 ganglion, shown in Fig. 11 at b'. The actual diameter of the cell is .015 mm.; the 

 actual diameter of the nucleus is .0065 mm. 



