28 
Poisonous Arthropods 
to form an organ for piercing and 
sucking. This is well shown by the 
accompanying illustration (fig. 16). 
Theupper lip, or labrum, ismuch 
reduced and immovable, the lower 
lip, or labium, is elongated to form 
a jointed sheath, within which the 
lance-like mandibles and maxillae 
are enclosed. The mandibles are 
more or less deeply serrate, depend¬ 
ing on the species concerned. 
The poison is elaborated by the salivary glands, excepting, possi¬ 
bly, in Belostoma where Locy is inclined to believe that it is secreted 
by the maxillary glands. The salivary glands 
of the Hemiptera have been the subject of 
much study but the most recent, eomprehen- 
sivepvork has been done by Bugnion and Popoff, 
(1908 and 1910) to whose text the reader is 
referred for details. 
The Hemiptera have two 
pairs of salivary glands: the 
primary gland, of which the 
efferent duct leads to the 
salivary syringe, and the 
accessory gland, of which the 
very long and flexuous duct 
empties into the primary duct 
at its point of insertion. 
Thus, when one observes the 
isolated primary gland it appears as though it 
had efferent ducts inserted at the same point. In 
Nepa and the Fulgoridce there are two accessory 
glands and therefore apparently three ducts 
at the same point on the primary gland. The 
ensemble differs greatly in appearance in different 
species but we shall show here Bugnion and 
Popoff’s figure of the apparatus of Notonecta 
maculata, a species capable of inflicting a painful 
17. 
Salivary glands of 
Notonecta maculata. 
After Bugnion and 
Popoff. 
18. Pharyngeal syrinve or 
salivary pump of Ful- 
l“";a*Pop T’ bite on man (fig. i 7 ). 
