Hen'chmax. — Nervous System of Liiuax. 



PLATE VIII. 



Fig. 90. (See explanation of Fig. 95, Plate VII.) The 82(1 section ; it passes 

 through the ocular tentacle, showing in section tlie cerebral invagi- 

 nation and ganglion of the right side. X 100. 



" 97-100. Posterior faces of transverse sections, the right side a little in ad- 

 vance of the left, from an embryo of the fourteenth claij. Killed in 

 Perenyi's fluid, stained in picro-carminate of lithium. — Figs. 104, 

 106; also Plate IX. Figs. 115-120, and Plate X. Figs. 121, 12.3, 125, 

 12G, belong to the same series as Figs. 97-100. The sequence of 

 sections is : — 



Section 81, 87. 92. 98. 102. 104. 109, HI, 113, 11-3. 115, 121, 

 Figure 97, 119, 98, 99, 118, lUO, 115, 110, 104, 117, 12;), 120, 

 122, 122. 127. 1"9. 

 106, 125, J 21, 1::G. 



" 97. The 81st section ; it passes through the pedal ganglia, a few sections be- 

 hind the posterior commissure, x 100. 



" 98 and 99. The 92d and 9Sth sections ; they pass through the pedal ganglia 

 between the two commissures, x 100. 



" 100. The 104th section, two sections m front of the anterior commissure. It 

 shows the right otocyst m addition to the radula sac and pedal gland, 

 x 100. 



" 101,102. (See explanation of Fig. 95, Plate VII.) 



" 101. The 52d section of the series, showing the abdominal ganglion, and a 

 cross section of the cerebral, buccal, and both pedal commissures. 

 X 100. 



" 102. The oGth section ; it passes through the visceral and buccal ganglia of 

 the right side, and a portion of the abdominal ganglion. It sliows 

 the cerebral and pedal commissures, as well as a sagittal section of the 

 foot gland. X 100. 



" 103, 10.3^. Tlie posterior surfaces of transverse sections from an embryo of 

 the seventeenth da ij. 0..33% chromic acid; alcoholic borax-carmine. — 

 Additional sections from tliis series are shown in Figs. 105, 108-113, 

 and Plate X. Figs. 122, 127. The sequence of sections is indicated by 

 the following : — 



Section 111, 176, 1 8 0, 186, 187. 194, 211. 212. 21 7. 225, 225. 

 Figure 103^ lO'JTlTO, HI, 112, 11.3, 103, 105, 122. 108, 127. 



" 10.3. The section passes through the cerebral ganglia in the region of the 

 cerebro-pedal connective. The wall of the body is not rei)rescnted, 

 but merely the ganglia, together with the oesophagus, the ducts of the 

 salivary glands, the radula sac, and the right ocular tentacle, x 140. 



" 103*. This section (111th) passes through the pedal, pleural, and viscenil 

 ganglia in the region of the pleuro-pedal connective. A large nerve 

 passes from the dorsal margin of each pedal ganglion to the lateral 

 wall of the body, x 83. 



(See obverse. ) 



