OF SUCTION IN LYGUS PABULINUS. 715 
positions by their own elasticity alone or that of the side-walls of 
the head. ‘They are brought to their original positions by the 
antagonistic muscles. 
The protractors are the chief agents in bringing about pro- 
trusion of the mandibles. 
(5) The Protractors of the Maxille. (Text-figs. 16, 19, 21, etc., 
Mx.P.) 
They are attached at one end to the sides of the maxillary 
Text-figure 24. 
Lygus pabulinus. 
Hand section, showing the styiets in the plant-tissue. Stained with saturated 
picric in 90 per cent. alcohol. Ob. 3 & Oc. 4. 
For explanation of the lettering see p. 693. 
9 4S Now MUILIEX, 49 
Proc. Zoou. Soc. 
