252 J. B. JOHNSTON, 
basal part of epiphysis; b. M bundles of Meynerr just as they leave 
the ganglia habenulae (g. hab). 
Fig. K. Sagittal section of the dorsal part of the ’tween brain. 
b. M bundle of Meynert; c.long.bdl common longitudinal bundle; c.p 
commissura posterior; ¢.swp commissura superior or habenularis; dec. d 
dorsal decussation; d.sac dorsal sac; ep.c epiphysial commissure; ep.s 
epiphysial sac; f.b.ven fore brain ventricle; g.hab ganglion habenulae; 
gid.p pineal stalk; n.ant nucleus anterior; nuc.praet nucleus prae- 
tectalis; pl.ch plexus choroideus, separating the cavity of the dorsal 
sac from the fore brain ventricle; tr.olf-hab tractus olfacto-habenularis; 
tr. thal-mam tractus thalamo-mammillaris. 
Fig. L. Epithelium of the saccus vasculosus. bl.c blood corpuscles 
in the blood spaces of the connective tissue layer; c.c ciliated cells; 
n.bdl bundle of nerve fibres; n.f nerve fibres from the bases of the 
ciliated cells; s.c supporting cells. 
Fig. M. Schemes of the elements of the commissura ansulata, A in 
sagittal section, B in frontal section. In A the position of the arabic 
numerals indicates the relative position of the various bundles. 1 fibres 
from commissural cells; 2 tractus tecto-lobaris; 3 tractus tecto-bulbaris ; 
4 tractus bulbo-tectalis; 5 fibres from the cells of the end-nucleus of 
Meynerv’s bundles; 6 arcuate fibres from the acusticum; 7 fibres from 
the Acusticuszellen of GoronowITscH; 8 decussation of Mzynert’s bundles. 
Fig. N. Horizontal section of the nucleus taeniae. op.n optic 
tract in lateral wall of thalamus; rec.pop recessus praeopticus. 
Fig. O. Horizontal section of the lateral wall of the olfactory 
lobe. f.b fore brain; C cell of Casau; f.olf olfactory fibres; g granule 
cell; gl glomeruli; m mitral cell; s.m small mitral cell; sp spindle cell; 
st stellate cell of the granular zone; st.gl stellate cell of the glomerular 
zone; II cell of the II type. 
Fig. P. Olfactory lobe. A stellate cell of the superficial zone. 
Fig. Q. Olfactory lobe. A spindle cell (sp) and two granule 
cells (g). gl glomeruli formed in part by dendrites of these cells. 
Fig. R. Olfactory lobe. Two cells in the glomerular zone, the 
upper one of which seems to have a short neurite. From adult fish. 
Fig. S. Details of olfactory fibre endings. Camera. 
Fig. T. Four olfactory glomeruli, camera drawing. f.olf olfactory 
fibre; gli a glia fibre. From adult fish. 
Fig. U. Olfactory lobe. A typical glomerulus, consisting of a 
mitral cell dendrite (m) and of several dendrites of other cells (d). 
f.olf olfactory fibres ending in the glomerulus. From adult fish. 
Fig. V. Horizontal section of the vagus lobe in a Catostomus embryo. 
c.b cervical bundle; c.inf.H commissura infima Halleri; c.g central 
grey matter; L.v lobus vagi. 
Fig. W. Medulla of frog. A and B sections through the com- 
missura infima Halleri (c.inf. H). C and D sections through the fasci- 
culus communis (f.c) farther forward. c.c canalis centralis; JV fourth 
ventricle; d.h dorsal horn. 
