142 Transactions of the Royal Microscopical Society. 
side of tlie under lip. The duct consists of an epithelial layer of 
cells, within which is a structureless membrane, strengthened, as 
is so often the case with the ducts of glands, by chitinous ridges, 
which give it very much the appearance of a trachea. 
The cephalic salivary glands (Plate CLXXXIX., Figs. 1-3, c s ; 
Plate CXC., Figs. 2 and 3, cs ; Plate CXCI., Fig. 3, c s; Plate 
CXCII., Fig. 3) are situated on each side of the head, in the 
space between the supra-oesophageal ganglion, the eyes, and the 
antennae. They consist of a number of short, stout tubules, some 
of which are branched at the base ; in F. rnfa there are about 
30, in other species the number is considerably less. They are 
of a yellowish hue, and, after combining to form a very short duct, 
open into the pharynx. 
The labial salivary glands lie on the under side of the mouth ; 
they are globular in form, and composed of a number of glandular 
cells (Plate CXCII., Fig. 4), each with a thin hair-like duct ; these 
ducts, according to Meinert, open into a common receptacle. 
In addition, there are also two pharyngeal salivary glands, 
which were, I believe, first observed by Meinert. According to his 
description, if I understand it correctly, the gland consists of 
about 20 cells, each with a duct which opens directly into the 
pharynx, by a separate orifice in the pharyngeal plate. 
Thus, then, these glands are curiously dissimilar in structure. 
It seems not improbable that they differ somewhat in the nature 
of the secretion to which they give rise. Wolff seems at least to 
have satisfied himself that this is the case in the hive bee. 
