772 Wisconsin Academy of Sciences, Arts, and Letters. 
to which any reference can be found is by Roletajew (19) who 
describes the salivary glands as paired, oval, acinose glands sit¬ 
uated in the prothorax near the first thoracic ganglion. Small 
ducts in each gland lead into the larger ones nntil there is 
finally a large duct whiqh empties into a reservoir. “Ein jeder 
Speichelgang erweitert sich am vorderen Ende zu einem Speich- 
elsack oder Reservoir’ 7 . There is a short duct from each res¬ 
ervoir, the two joining to open by a single outlet near the base 
of the hypopharynx on its under surface. 
In Libellula Jf-maculata the salivary glands are situated, as 
in other dragonflies, in the prothorax; there is but a single pair, 
and these lie at either side of and generally a little ventral to 
the oesophagus. In some specimens the glands extend back 
a short distance into the mesothorax. Each gland has a slight¬ 
ly bilobed appearance and is, in part, divided into an anterior 
and a posterior portion (fig. 32). A duct leaves the anterior 
margin of each gland; it runs forward through the cervical 
region and, upon entering the head, turns ventrad and takes 
a slightly posterior direction until it reaches the reservoir, which 
lies at the base of the hypopharynx, one end of which it en¬ 
ters. From the other end of each reservoir a short duct passes 
towards the floor of the buccal cavity; these two short ducts, 
each .28mm long, unite before emptying into the buccal cav¬ 
ity. The duct, both upon entering and leaving the reservoir, 
is of the same structure, it is in each instance covered for a' 
short distance by a prolongation of the wall of the reservoir; 
this covering gradually decreases in thickness (fig. 33). 
Each salivary gland of Libellula J^-maculata is flattened and 
irregular in shape, broad distally but pointed at the anterior 
end from which the duct leaves. Each gland is composed of 
a number of small lobes which are in turn made up of many 
smaller acini. Within and near the center of each acinus is 
a small collecting duct which runs between the cells. These 
ducts unite with others in the small lobes; the ducts from the 
lobes unite with or empty into those from other lobes until 
all finally assemble in the large duct which leaves the anterior 
end of each gland. Each acinus is composed of a number of 
