C. Hay Murray 
303 
the bug has been allowed to feed without hindrance, the blood is occa¬ 
sionally seen to be filling the pouches above mentioned, while between 
each two “ pouchfuls ” there is a short space of intestine with no blood 
or other contents.. In one case there were seen three such collections 
between which there were no contents, the walls of the intestine being 
quite occluded. This may be due to the bug having to make the most 
of its opportunities for feeding, and when the stomach is full, having to 
utilise the anterior portion of the intestine for storage. It is quite 
possible, however, that the condition may be a result of death throes, as 
the bugs were chloroformed soon after their meal, but the writer thought 
it well to put the fact on record. The posterior end has no pouches, is 
very much thinner than the other, and the contents, when present, are 
of the afore-mentioned sepia colour. 
Next comes the rectum, the junction between which and the intestine 
bears the Malpighian tubules which are four in number. They are 
individually longer than the whole alimentary tract, being indeed from 
one and a half to twice the body length. The whole alimentary tract 
in a famished bug is three times the body length, while in a fed one it is 
more than twice. Probably the difference due to feeding accounts for 
Landois’ observation that the alimentary tract is not twice the length 
of the body (Fig. 28). 
The rectum is practically always full of dense dark sepia-coloured con¬ 
tents, of a texture strongly resembling lamp-black. Sometimes, however, 
the colour is of a light brownish-yellow, in which case the dark granules 
are not present. This difference does not seem to depend on sex, and 
is the exception rather than the rule, so possibly it may be a pathological 
condition. 
The rectum is heart-shaped and opens to the exterior at the apex of 
the body in both sexes. In the male the anus is slightly to the left of 
the iniddle line. In the immature bi:g it opens on the ventral surface. 
If the contents of the rectum be examined microscopically, the first 
thing noticed is the presence of innumerable whole blood corpuscles 
mixed up with portions of others, the whole mass being coloured brown 
and containing fine brown granules. Dilution of the contents shows 
that the whole corpuscles still retain their normal life colour. A bug 
which had not been fed for at least three weeks, and whose rectum was 
the only opaque portion of its alimentary system, got an unrestricted 
meal. After feeding it ran about on a sheet of paper, and very shortly 
“ backed ” unexpectedly and passed two small drops of faecal matter. 
These were fixed, and on being examined under the microscope were 
