150 JouRNAL OF COMPARATIVE NEUROLOGY. 
and the neurones intervening between it and the body muscu- 
lature comprise the other. 
c. Nucleus Postolfactortus.—The nucleus postolfactorius is 
a collection of neurones at the ventro-lateral surface of the 
striatum near its anterior end (Fig. 31, z. go.). This nucleus 
is sharply demarcated from the general striatum by the close- 
ness with which its neurones are arranged; Fig. 36 shows the 
morphology of five neurones as they lie in place. The periph- 
eral zone is occupied by fibres, and also by the dendritic tips 
of the neurones themselves. The cell-bodies lie ina densely 
matted tangle of nervous processes just internal to the periph- 
eral layer. A cell-body is somewhat larger than one from the 
epistriatum. The form ranges from pyramidal to elongated 
oval. The dendrites are rather few in number, relatively short, 
branching dichotomously once or twice. They are usually 
stout processes, gnarled, rough, and irregular, with but few 
true gemmules. Some neurones send their dendrites radiately 
in all directions ; others take a more or less tangential course ; 
still other are extended between the zone of nerve-fibres at the 
periphery and the striatum within. A conspicuously felt-like 
tangle is thus given by all of these interlacing dendrites. 
The axone arises from one ot the dendrites, so far as ob- 
served. It passes into the tractus olfacto-habenularis, coursing 
posteriorly along the ventral border of the forebrain for ultimate 
termination in the nucleus habenulae of the interbrain; see 
Section VII. 
The internal structure of a postolfactory neurone is not 
of a pronounced motor type. The nucleus is always so large 
that it touches the periphery of the cell at one or more points, 
leaving the cytoplasm almost entirely in the bases of the den- 
drites. The chromatin lies in a fine reticulum. There may be 
two nucleoli. The tigroid substance is disposed in triangular 
or irregular bodies of smaller size than those noted for the 
striatum. These features are shown in Fig. 67. 
The nucleus postolfactorius receives many olfactory fibres 
of the second order. A fibre entering for termination here is 
seen in Fig. 36, of. f. This nucleus evidently holds a very dif- 
