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The cells of the intestine have large nuclei. The 
protoplasm is finely reticular, and stains less deeply 
than that of the cells of the mid-gut. Stained with 
Heidenhain’s haematoxylin, no granules are present as 
in the cells of the mid-gut. They have no striated 
border. 
In the rectum the cells become small and flattened. 
There are here, however, bodies usually termed rectal 
glands. These are papillae covered with a single layer 
of much hypertrophied cells resembling those lining 
the small intestine and colon. 
The Salivary Glands. —The salivary acini lie in 
a cleft in the fat-body, which latter comes in close 
contact with the glands. Each gland acinus consists 
of a single layer of large cells, limited externally by a 
delicate sheath (basement membrane) and internally 
by the intra-glandular duct wall. 
In Anophelines the intra-glandular duct becomes 
larger as it approaches the termination of the acinus, 
and forms a large cavity. 
In Culicines the duct remains of the same diameter 
throughout the acinus, and terminates abruptly near 
the end of the acinus without any dilatation. 
In both Culicines and Anophelines there are two 
types of gland acinus. These are recognizable both 
in the fresh gland and in fixed specimens. From their 
appearance in the latter they may be termed 
(1) The granular type. 
(2) The clear or colloid-like type. 
The Granular Type. —The greater portion of the 
acinus consists of cells whose nucleus and protoplasm 
has been pushed to the outer portion of the cell by a 
large mass of secretion which occupies almost the 
whole of the cell. In the fresh gland this secretion 
appears as a clear, refractive substance, and can, by 
