1172 
Journal of Agricultural Research 
Vol. XXVIII, No. 12 
slender spur dorsad and laterad. These serve as the tendonous insertions of 
short muscles inserted on the anterior wall of the cranial capsule. 
The mandibular apodemes also claim attention here. These are slender 
tapering chitinous spines which arise from the base of each mandible on its mesial 
side and are directed caudad and dorsad (PI. 1, A, RAp). These, as their name 
indicates, serve as tendonous insertions for the large adductors of the mandibles. 
These spines are hollow for a considerable part of their length and are both 
accompanied and produced by corresponding involutions of the hypodermis. 
White (50) has already called attention to the minute spines of the larval 
cuticle. These are more or less irregularly scattered over the surface of the 
cuticle of the head and trunk, the distance between them varying from 5 to 30 
microns. Their length does not exceed the thickness of the cuticle, which is 
5 to 6 microns. On the mesial surface of the tips of the maxillae these spines 
are however quite numerous, while the extreme tip of the labrum is clothed with 
thick-set chitinous spines, longer and more slender than those found elsewhere. 
The head capsule and endoskeleton of the head of the bee are, except for slight 
differences in proportion, identical with those of the larva of Vespa, as described 
by Kirmayer (26). 
NERVOUS SYSTEM ' 
The general features of the nervous system of the bee larva have already been 
described in an earlier publication (36). These features indicate on the whole 
a conformity to the simple type found in many insect larvae. In the bee larva 
this simple type persists throughout larval existence, although histological 
changes are continually taking place, especially in the brain, in the direction of 
the imaginal condition. In comparison with certain other insect larvae, such as 
Corydalis (13), the nervous system of the bee seems deficient, particularly with 
regard to the sympathetic nervous system. This may, however, only argue a 
deficiency in observation. The small size of the bee larva and the abundance 
of fat tissue, whicfi more or less completely fills all the spaces of the body cavity, 
clinging tenaciously to whatever organs lie adjacent, constitute no small obstacle 
to successful dissectio n, while the tracing of nerves in sections has not been found 
satisfactory. 
The nervous system of the bee larva has never been described or illustrated 
in detail. Probably the only figures worth mentioning are those of Brandt (5), 
and the one shown in the Leuckart and Nitsche wall charts (31), a figure widely 
copied in text books and evidently borrowed from Brandt. These show little 
more than the general plan of the nervous system, the shape and proportions of 
the brain and circumoesophageal connections being incorrectly represented. 
Brandt's figure shows correctly the number and relative size of the ganglia in the 
ventral chain, and also the paired connections and lateral nerves. 
In describing the nervous system it may be conveniently divided into the brain, 
the ventral nerve cord, and the stomatogastric nervous system. The following 
description, unless otherwise stated, is to be understood as applying to the mature, 
or nearly mature, larva. 
BRAIN 
The brain is of relatively large size, almost completely filling the upper part of 
the head capsule (fig. 1, Br; PL 1, B, C). It is divided symmetrically into 
two expanded crescentic halves united on their convex borders by the supra- 
oesophageal commissure (PI. 1, B, Sup Com ). Seen in face view, each half presents 
a mesial pyriform division, the slender inferior ends of which form the crura 
cerebri (CCer) connecting the brain with the suboesophageal ganglion (SoeGng); 
above these follow in order the small but prominent tritocerebrum (3Br), the 
