ANATOMY OF THE NERVE CENTRES. 457 
Diet], although he does not mention the procerebral lobes, 
has figured them in the Bee (Apis mellifica) [175, Pl. XXXVL., 
Fig. 1], in which they are apparently far larger than in the 
Fly. The nodulus is also larger, and is shown in Dietl’s 
figure to be connected with the radiating fibres of the corpus 
centrale. 
There is -also a distinct indication of the procerebron in one 
of Cuccati’s figures [186, Pl. XX., Fig. 61. It is to be regretted 
that all Cuccati's figures are too small, and are insufficiently 
described in the text. 
In 1870 I first discovered the procerebron in the Blow-fly 
by removing the surrounding parts. I gave a figure of the 
appearance they presented in a preparation made by dis- 
section, displayed by the pressure of the cover-glass [62, 
Pl. VII., Fig. 4], and I was able to state, as the result of the 
rude methods employed in those days, that they are peduncu- 
lated lobulated organs united by a well-marked median com- 
missure. At the same time I suggested that they are possibly 
analogous to the cerebral lobes of vertebrates, an opinion 
which has been rendered more probable by my more recent 
researches. 
I suspect that the parts described by Viallanes in the Cricket 
as the lateral lobes of the median protocerebron consist in part 
of the representatives of my procerebron, and in part of my 
thalamic lobes. 
The Corpus Centrale (Fig. 59) is a complex commissure, 
situated in the cavity of the cerebron, behind the nodulus, and 
in front of the pyramidal ganglion. It is largely developed in 
all the Insecta, but is apparently entirely wanting in the 
Crustacea. Perhaps this remarkable body may be best de- 
scribed by comparing it to a broad band folded S-wise. The 
upper limb of the S forms the capsule (Fig. 59, c); it over- 
laps the rest laterally, in front, and behind. The remainder 
of the S forms what has been termed the ellipsoid body (e). 
Between the capsule and the ellipsoid body is the hilus, into 
which fibres from the nodulus pass; these form the fillet of 
the nodulus. 
