OF SUCTION IN LYGUS PABULINUS. 699 
ends internally in a swollen base. These swollen bases, which 
are oval, have their importance in history, which has been referred 
to above. They are known as the retort-shaped organs of 
Mecznikow, or the Taschen-formigen organs of Heymons (text- 
figs. 5, 6, 20, 21, Poc.Or.). 
Text-figure 6. 
Lygus pabulinus. 
Reconstructed from numerous vertical sections, showing the relation of the 
muscles to the stylets, the pump, etc. Ob. 3 & Oc. 4. 
For explanation of the lettering see p. 693. 
There is no trace of the maxillary groove upon the swollen 
bases, but it begins a little below. The structure of the groove is 
the same here as described in the external part, though on a 
minute scale. The stylets are, of course, separate in the head, as 
they pass one on either side of the pharynx (text-figs. 1, 5, 6, 
11-19). 
Proc. Zoot. Soc.—1914, No. XLVIII. 48 
