NOSEMA-DISEASE. 
a slender tube traversing the entire thorax. In the anterior part of 
the abdomen the oesophagus expands into a large thin-walled sac 
which is known as the honey stomach (HS) ; next is the short neck- 
like portion, the proventriculus (Pvent); then comes the large U- 
shaped portion, the stomach or ventriculus (Vent), an organ with 
thick walls and many annular constrictions. Following the stomach 
is the short, narrow 
and coiled, small in- 
testine (SInt) having 
a circle of about one 
hundred long, greatly 
coiled, blind, thread- 
like tubes opening 
into its anterior end. 
These tubes are the 
Malpighian tubules 
(Mai). Following the 
small intestine is the 
large intestine or rec- 
tum (Red). When 
bees have been con- 
fined for some time 
this latter portion of 
the canal is found dis- 
tended with material 
to be voided. 
Since the stomach is 
always invaded by the 
parasite in Nosema- 
disease, and the Mal- 
pighian tubules occa- 
sionally are, a further 
description of the 
structure of these or- 
gans seems warranted. 
The stomach (fig. 
1, Vent) is a relatively 
thick-walled organ 
lying U-shaped within 
the abdomen. When 
removed and straight- 
ened it is seen to be in general cylindrical but somewhat spindle-shaped 
in form. (PI. I.) Circular constrictions present give to it a segmented 
appearance. The number and distinctness of these transverse mark- 
ings vary somewhat. The size of the organ and its color vary also. 
The color varies within wide limits, being usually some shade of 
Slur 
Vent 
Fig. 1.— Alimentary canal of worker bee: Pharynx (Phy), oesophagus 
((E), honey stomach (HS), proventriculus (Pvent), stomach or 
ventriculus (Vent), small intestine (SInt), and large intestine or 
rectum (Red), rectal glands (RGl), Malpighian tubules (Mai), 
Salivary glands of head (2GI) and thorax (SGI), and pharyngeal 
glands (1GI) are also shown. (Snodgrass.) 
