402 ANNUAL KEPORT SMITHSONIAN INSTITUTION, 1919. 
of two compartments (/ and g). Six tubes appear to leave the 
stomach. The first {Int) issues from the anterior end of the front 
stomach compartment and goes rearward in many crosswise loops 
along the back till finally it ends in the pear-shaped rectum {Red), 
which opens to the exterior through the anus. This tube (Int) must, 
therefore, be the true intestine. From the rear end of the second 
stomach compartment, which is of an orange-brown color, there issues 
a tube (A) of the same color, which goes backward in many loops 
and folds but eventually turns forward again and penetrates the 
stomach at the constriction between its two compartments. On the 
same line there issue four very small whitish tubes (/) which form 
two loops inextricably tangled amongst the folds of the intestine. 
At first sight this alimentary structure is a puzzle — ^the intestine 
issues from the front end of the stomach, while the tube arising from 
the rear end of the stomach, where the intestine should begin, turns 
back on itself and reenters the stomach. The explanation is simple, 
however, and is easil}^ found by dissecting the first stomach com- 
partment. The tube (h), entering the rear end of this compartment, 
does not open into the stomach cavity but merely penetrates between 
its muscular v/all and its interior lining, where it goes forward in 
many zigzag loops and issues at the top as the tube hit The tubes 
i arise from the enclosed end of the intestine (Int) in two pairs from 
two short basal tubes and go backward in the stomach wall from 
which they issue, as shown on the plate, at the front of the second 
stomach compartment. These are the Malpighian tubules which 
function as the kidneys in insects. 
Thus the puzzle of the anatomy is solved, but we are not sure 
of any reason for such an unusual state of things. Some entomolo- 
gists, however, have supposed that the arrangement affords a short- 
cut to the intestine for some of the waste matter in the stomach, 
which can soak through into the upper end of the tube h and thus 
go direct to the intestine (Int) , while the nutritive material goes on 
by way of the long loop (A, h, h). They would, hence, name the 
first compartment of the stomach tlie " filter chamber." But it is not 
clear how the tubes can select waste matter in solution from nutri- 
tious matter in the same liquid. 
Both the stomach and the sac of the rectum are usually filled, and 
frequently tensely distended, with a clear liquid. The presence of 
such an elaborate digestive system, with its retaining parts thus 
filled with liquid, only adds confirmation to the observed facts of the 
cicada's feeding already recorded. The two stomach sacs (/ and g) 
lie in the narrow, almost vertical, space between the Y)osterior 
phragma (fig. 7, PpK) and the anterior end of the air chamber. The 
tubular parts are packed into the flat space above the chamber, a 
