724 MR. P. R. AWATI ON THE MECHANISM 
Text-figure 28. 
tig. 
Upper wall of 
the Pharynx. 
Nucle/. 
Nerve fibres 
Joining the lobes. 
Nerves to the 
Periphery, 
ee Soonr US. 
Vertical section of the gustatory organs with the cribriform plate, showing 
nerves passing to the periphery, ete. Ob. 6 & Oc. 4. 
For explanation of the lettering see p. 693. 
Tur PumMP-APPARATUS, OR WANZEN-SPRITZE. 
This apparatus is one of the characteristic structures of the 
Rhynchota, and has been described, though not in detail, by 
many writers. It was’ first discovered by Landois (28) in 
Cimex, and described later on by Wedde (46), in some: detail, 
in Pyrrhocoris. 
It has been found in almost all rhynchotous forms except the 
Anoplura. Wedde has attached so much importance to it as to 
divide the Hemiptera into two groups: (i.) Rhynchota setifera— 
with the pump-apparatus, and (ii.) Pediculide—without it. It is 
possible that, in the Pediculide, it may have escaped the notice 
of investigators, since it must be very minute. I am the more 
encouraged in this belief because Grove (16) says that the pump- 
apparatus is not found in Siphonophora rosarum (a tolerably big 
form), though he has figured it in his drawings (fig. 7 loc. cit.). 
He further says, ‘‘In exactly the same position in the small 
pointed under-lip.... which closes the mouth on its posterior 
margin, where the above authors have described the salivary 
pump, is a small U-shaped rod of solid chitin.” This small rod 
of solid chitin is nothing but the pump-cylinder. 
