C. Hay Murray 
317 
According to the “Textbook” the muscles moving the crop roof 
arise from the dorsal and lateral walls of the head. This last is wrong, 
as may be seen on reference to Figs. 25 and 26. 
The authors omit all reference to the thickened “ bottle neck ” rim 
at the anterior end of the crop, through which the stylets pass, thus 
linking up their cavity with that of the pharynx, and they say “ the 
means by which the food canal in the proboscis is connected with the 
pharynx has not been made out. They have no chitinous continuity ” 
(p. 514). 
The constrictions mentioned as being permanently on the stomach 
have been shown by the writer to be only temporary. 
Their statement that the posterior end of the gut, i.e. the intestine, 
“ never contains fresh blood ” (p. 515) has been shown to be wrong, as 
also has been the suggestion that only in a fasting bug does the stomach 
contain air. 
They make no mention of the bands of dark glandular cells on the 
stomach walls. 
When discussing the malpighian tubules they say “ their low 
insertion being a remarkable feature.” What is meant the writer 
cannot say, as their position at the junction of intestine and rectum 
is quite normal. 
As was the case with Landois, the authors failed to trace the ducts 
leading from the salivary glands to the reservoirs, and thus they say 
that there are “ two pairs of sahvary glands.” 
Messrs Patton and Gragg describe as follows a complicated salivary 
pump, the essentials of which are ; 
“ A vase-like cup of chi tin with its narrow end directed to the 
point at which the two mandibles come in contact with one another. 
The broad posterior end is closed in by a membrane in the middle of 
which is inserted a short rod of chitin.” 
“ Contraction (of muscle fibres) pulls the rod and therefore the 
membrane away. . . creating a negative pressure, which negative pres¬ 
sure will therefore result in drawing the saliva from the glands into 
the pump.” 
“ Presumably there is some valve which prevents ingress of blood 
into the pump when in action.” 
“ There are no muscles which could force the piston rod forwards ” 
(pp. 517-518). 
There are on Plate Lxiv two sketches relating to the above (figs. 
4 and 6). Fig. 4 is the pump of A. rotundata, while fig. 6 is that 
