Hamaker. — Nervous Syst. Nereis. 
Fig. 1. 
Fig. 2. 
Fig. 3. 
Fig. 4. 
Fig. 5. 
Fig. 6. 
Fig. 7. 
Fig. 8. 
PLATE 1. 
Diagram showing the disposition of the nerves of the brain and sub- 
cesophageal ganglion in dorsal aspect. In order to show the commissural 
ganglion and its nerves, the right anterior eye has not been indicated; 
I, V, a, 8, y, nerves to the proboscis; II, nerve to the antenna; III, IV, 
VII, 5, «, G 7, nerves to the muscles and the general surface of the head; 
6, commissure between the anterior and posterior cirrus ganglia; VI, 
nerve to the palp; VIII, IX, X, nerves from the brain to the commis- 
sural ganglion; XI, XII, optic nerves; XIII, nerve of the ciliated 
groove; XIV, three openings in the dorsal surface of the brain capsule, 
through which loose bundles of nerve fibres pass to the integument of 
the mid-dorsal region of the cephalic lobe. 
Para-sagittal section of a giant fibre to show the passage through it of a 
fibre of set B (compare Fig. 27). In this case the branching of the fibre 
B takes place within the giant fibre, and the axis cylinder of fibre B is 
shrunken. 
Cross section of a lateral giant fibre, to show the reticulum. 
Frontal section of the body wall between two parapodia, to show the rela- 
tive positions of nerves IV’, V’, and I’, and of the attachment of the 
longitudinal muscles and the dissepiment. 
Diagram of posterior aspect of part of a cross section, showing the dispo- 
sition of the parapodial nerves. The second and third parapodial nerves 
(compare Fig. 8) are designated by 2 and 3 respectively. 
Frontal section of a segmental ganglion, showing the intimate relation 
between the fibres of sets A and B (compare Fig. 27). 
Section similar to that in Fig. 6 showing the relation of the decussating 
parts of fibres 6B; also showing exceptional oblique course across the 
ganglion. 
Diagram showing the disposition of the segmental and parapodial nerves 
of a typical segment. JI, II, III, 1V, V, the five segmental nerves num- 
bered from in front backward. 1, 2, 3, 4, the four parapodial nerves. 
