716 LaurA FLORENCE 
mixture method introduced by Apathy (1912:464, 468; also Kornhauser, 
1916) was used, but it gave no better results than Gilson’s rapid method 
and involved many more steps. After double-imbedding it was found 
possible to make good series of longitudinal and transverse sections of 
5 microns, 74 microns, and 10 microns, in thickness. 
The reagents used for fixing were Zenker’s fluid, Bouin’s fluid, and 
Flemming’s weak solution. In every case the insect was chloroformed and 
its legs were cut off close to the thorax before it was placed in the reagent. 
Both the Zenker-fixed and the Bouin-fixed material were stained with 
hematoxylin and eosin, hematoxylin and orange G, and methylene blue 
and eosin. In addition the Bouin-fixed material was stained with Mallory’s 
anilin-blue connective-tissue stain, a combination used by Kingery (1916: 
292) in studying the intestine of the grasshopper. This stain differentiates 
the chitinized from the non-chitinized cuticula, the former staining red 
and the latter a clear blue, and also brings out strikingly the striations 
of the muscle fibers. The Flemming-fixed material was stained with 
iron hematoxylin according to the method of Heidenhain, and with 
safranin, a solution made of equal volumes of a water-soluble and an 
alcohol-soluble stain being used. 
All measurements given in the text were made with an ocular micrometer 
valued in terms of a stage micrometer used in a Zeiss microscope fitted 
with an objective A, 15 millimeters, and an ocular No. Z, and having a 
tube length of 160 millimeters. 
SUMMARY 
At the close of his paper on the mouth parts of the body louse, Harrison 
(1916 b:218) has pointed out the many resemblances found by himself and 
other workers between the Siphunculata (Anoplura) and the Mallophaga, 
particularly those of the suborder Ischnocera. The present study has 
served to again emphasize the general similarity in structure of the two. 
groups, and has brought to light some structures which have not yet 
been described in this order. 
No mention of the apodemes extending from the dorsal to the ventral 
surface of the thorax has been found in the literature. While the name 
suggested for them — the apodemes of the prothorax and the prosternum 
— is intended to call attention to their position in the anterior part of the 
thorax, it must not be forgotten that they probably originated as invagi- 
