— 205 — 
Plate VII. 
The illustrations of this plate are drawn from the microscope 
directly upon the stone, under the camera lucida. 
Fig. 63 & 64. Homarus vulgaris. (Magnified 350 diameters; Zeiss 
CC, 4.) Parts of a transverse (lig. 63) and a longitudinal 
(fig. 64) section through ventral ganglia. a — g Nervous 
processes from ganglion cells or branches springing from 
such processes. h Subdividing part of a nerve-tube. 
i Varicose nervous fibril. vf Varicose nervous fibril. 
I — 12 Parts of longitudinal nerve-tubes belonging to the 
longitudinal commissures. sf, sf' Slender nerve-tubes 
partly given off from these longitudinal large nerve-tubes. 
(From chromo-silver stained preparations.) 
» 65. Homarus vulgaris. (Magnified 11 50 diameters; Zeiss. 
Hom. im. '/iS' i-) P^i'^ of a transverse section through 
the dotted substance of an abdiminal ganglion, a — / Nerve- 
tubes, some of which are seen to subdivide. (Fixed in 
chromo-aceto-osmic acid; statned in accordance with Hei- 
denhain's hæmatoxylin method.) 
» 66. Nereis virens. (Magnified 950 diameters ; Zeiss. Hom. im. 
V185 I-) Part of a horizontal, longit. section through the 
dotted substance of the ventral nerve-cord. a The central 
vertical septum, dividing the nerve-cord longitudinally 
(compare fig. 10, a & fig. 14). tt, U\ Transverse, small 
and large, nerve-tubes crossing this septum. tt^^^ Trans- 
verse nerve-tubes passing to the root of a peripheral 
nerve, pt Large nerve-tubes passing to the root of the 
same nerve, t Small longitudinal nerve-rubes. It Large 
longitudinal nerve-tubes. n, ri Neuroglia-nuclei, situated 
longitudinally {n) or transversally (^^') in the dotted sub- 
stance. (Fixed in chromo-aceto-osmic acid, stained with 
Delafields hæmatoxylin.) 
Plate YIIL 
Fig. 67. Nereis virens. (Magnifid 620 diameters; Zeiss F, i. 
Cam. lue. from the microscope direct upon the stone.) 
Part of a horizontal, longitudinal, section through the 
ventral part of the ventral nerve-cord. ds, ds The dotted 
substance on each side of the central mass of ganglion 
