166 BULLETIN OF THE 
those described as lying between the two pairs of giant cells are my 
fourth pair. His figures do not fully agree with this, however. His 
Figure 2, Gz, shows the “anterior giant cells,” which are clearly my 
commissural cells ; Figure 11, Gz, which he regards as one of the same 
pair, has more of the appearance and position of a cell of the fifth pair. 
The dorsal cells are described as salivary glands (Spdz, Figs. 1, 2, 11), 
and it is curious that he has nowhere represented the prominent pro- 
cesses (stalks) of these cells, unless, indeed, they are the structures 
labelled Gz # (Fig. 12). Although the position is somewhat peculiar, 
they certainly look more like the stalks of the dorsal cells than like 
processes of the cells marked Gz in the same figure, which is his inter- 
pretation, since the latter usually extend directly backward. 
Biirger expresses a doubt that the posterior giant cells (i. e. my fifth 
pair) lie opposite each other. If not, it was because of some deformity 
or twisting of the head, as they evidently are opposite each other in my 
preparations (Figs. 63, 85). Instead of being nearer together than the 
other cells, as he maintains (p. 640), they are certainly farther apart 
than the components of any other pair (see my Figs. 63, 85). 
y. Fibrous Mass. — The central fibrous portion of the brain shows 
few definite points of structure. The fibres run in every direction ; one 
finds few commissural bands, and in general no fixed arrangement. At 
two points, however, one notices (Fig. 99) vertical bands of fibres which 
divide the brain into three parts, a central and two lateral portions, 
which in position correspond to the three divisions of the ventral nerve 
cord, which will be described later. The dorsal commissure (Plate VI. 
Fig. 80, coms. œ.) is very meagre, being cut in only two or three sections. 
The number of fibres in it is consequently small, but there are at least 
four large nerve processes ; two belong to the third or commissural pair 
of cells, the other two perhaps to the second pair. A few finer fibrils 
accompany these. 
In the female the brain measures only 0.08 mm. in length, and 
0.1 mm. in width. In consequence of its more compressed form, the 
cells stand closer together, and are more difficult to study. One finds 
exactly the same number of large ganglion cells, and they occupy corre- 
sponding locations. It may, then, be fairly assumed that the processes 
are distributed in the same manner, although I was unable to follow 
them as clearly as in the male. 
In total preparations (Fig. 63) one often sees groups of fibres passing 
anteriad from the brain into the front wall of the anterior chamber. As 
has been shown from sections, however, this is all solid tissue in front of 
