82 J. B. JOHNSTON, 
cells of transitional forms exactly similar to those described in the 
acusticum, measuring 16—20 by 160—240 u. The cells with smooth 
dendrites which were described as typical for the acusticum are 
present here also, and measure 12—32 by 32—144 u. Cells of 
Goual’s II type are present in rather greater numbers than in the 
acusticum. Finally there are very small cells, measuring 8—10 by 
10—16 u, which resemble the granule ceils of the granular layer 
of the cerebellum. In the lateral part of the lobus lineae lateralis 
these granule cells become more numerous, and on the lateral sur- 
face of the lobus there is a dense collection of such cells which 
may be traced forward into continuity with the granular layer of 
the cerebellum. This layer of granule cells is seen overlying the 
cerebellar crest in Phot. 14, which is a section just touching the ce- 
phalic end of the lobus lineae lateralis. I shall consider this special 
group of granule cells apart from the lobus lineae lateralis and de- 
scribe it in connection with the cerebellum (page 96). 
The neurites of the PURKINJE and other large cells in this lobe 
run ventrad around the cerebellar crest. Through the greater part 
of the length of the lobe these fibres pass around the internal 
(mesial) surface of the cerebellar crest, run through the acusticum 
to the base of the medulla and seem to comport themselves exactly 
as do the arcuate fibres from the acusticum. At the cephalic end 
of the lobe the cells send their neurites ventrad around the external 
(lateral) surface of the cerebellar crest which here begins to turn 
mesad to course around the border of the lateral lobe of the cere- 
bellum. These neurites run cephalo-ventrad so that they reach the 
base of the medulla in the region of the commissura ansulata. 
I think that they pass to the opposite side in this commissure, 
although the relations in this region are so extremely complicated 
as to make the determination of the course of specific fibres ex- 
ceedingly difficult. (Compare the analysis of the commissura ansulata 
below, page 205.) 
The fibres which find endings in the lobus lineae lateralis are 
chiefly those of the lateral line VII nerve. This nerve is divided 
into two nearly equal portions, the ventral one of which has been 
described above as entering the dorsal part of the acusticum, while 
the dorsal one enters this lobe. The fibres of the dorsal root break 
up in all parts of the lobus in relation with its cells. Besides the 
fibres of this root a considerable part of the fibres of the ventral 
root pass through the dorsal part of the acusticum, course around 
