1202 
Journal of Agricultural Research 
Vol. XXVIII, No. 12 
contain food vacuoles, nor do they in fact give any good evidence of being phago¬ 
cytic in character. This is in accord with the observations of Anglas (1) on the 
wasp and honeybee and P6rez (40) on the ant. 
The nuclei of the oenocytes are spherical or ellipsoid and contain a large 
number of subecpial chromatin granules uniformly distributed (PI. 8, B, Oen). 
The cytoplasm is dense, staining intensely in both haematoxylin and eosin, and 
exhibits variations in density which give it a characteristic mottled or marbled 
appearance. 
EXCRETORY OR URATE CELLS 
In the mature larva of the honeybee these cells, as stated by Anglas, occur 
only in small number. They are found in the abdomen, interpolated singly 
here and there among the fat cells, with which they are always closely associated. 
As shown in Plate 8, C, u y they are cells of somewhat irregular form, having a 
diameter about half that of the fat cells. The nucleus is spherical and contains 
a relatively scanty amount of chromatin in the form of small granules. The 
cytoplasm has a fine and regular alveolar structure, and in sections usually 
appears pale, having slight affinity for stains. In a very young larva (two days 
old) the excretory cells (PL 8, D, u) appear to be more numerous than in older 
larvae, and may be found in groups or clusters. They are here rendered more 
conspicuous both by their relatively greater size, which is equal to that of the 
fat cells, and more particularly by the greenish-yellow color of their cytoplasm. 
Under high magnification (1/12 homo, immers.) minute refractive greenish par¬ 
ticles may be seen within the alveoles. 
The general resemblance of the excretory cells to the fat cells and their close 
association with them at this stage argues strongly for a community of origin, 
as assumed by both P6rez (40) for the ant and Anglas (1) for the wasp and bee. 
Berlese (3) suggests that the excretpry cells and the oencocytes have had a 
common origin. In Plate 8, D, an oenocyte from the same section as the other 
cells is introduced for comparison. The discrepancy in size and in other char¬ 
acters between this cell on the one hand and the fat and excretory cells on the 
other is sufficiently obvious. Moreover, the oenocytes are well differentiated 
and possess most of their distinctive characters even at the time of hatching (36 ). 
RUDIMENTS OF GONADS 
OVARIES 
In the mature worker larva the ovarian rudiments are two small flat structures, 
one situtated on either side of the dorsal mid-line in the 5th abdominal segment 
(PI. 8, G, Ov.). In side view each of these rudiments (PL 8, I) presents a trape¬ 
zoidal outline, the dorsal and ventral margins being parallel, while the two ends 
are abruptly narrowed to form slender tapering filamentous processes which 
extend cephalad and caudad along tj^e ventral side of the heart into the 4th and 
6th abdominal segments respectively. Exclusive of these processes, the length 
of the rudiment doeg not exceed half of that of the segment in which it lies. The 
ventral margin is thickened, the dorsal margin thin, so that in section each 
rudiment presents a pyriform outline (Pl. 8, G and H, Ov.). 
Histologically each rudiment is composed principally of a close network of 
minute branching connective tissue cells (Pl. 8, H) enclosed by an epithelium made 
up of minute flat cells and covered externally by a cuticular tunic. From the 
dorsal border delicate cell-strands, clothed with a membrane continuous with the 
tunic, pass to the ventral wall of the heart on either side of the mid-line, thus 
acting as suspensory ligaments. The dorsal borders of the rudiments lie close to 
the mid-line, but their ventral borders lie farther apart, so that the mesial surfaces 
