STRUCTUEK AND BIOLOGY OP SCHIZONEURA LANIGBEA. 679 
lias described its stmctare in Phylloxera vastafcrix. 
Kei’sliaw (1911) has recently described the structure of 
the pump in Pristhesancus papuensis^ a species in -which 
this organ is well developed. My observatious on the 
salivary pump agree closely with those of Dreyfus (1894) in 
Phylloxera vastatrix. 
When seen in longitudinal section (fig. 24), the salivary 
pump in Schizoneura lanigera consists of a salivary 
chamber (s.c.) or “Kolben,” whose outer walls form the cylinder 
[cd.) and a strong, distal portion or shaft, which is strongly 
chitinised and laterally compressed, its chitiuous walls being 
continuous with that of the hypopharynx. 
At its closed proximal end, as will be seen in vertical 
sections through the head (figs. 31, 33), the cylinder is greatly 
enlarged, its outer walls being strongly chitinised. Its 
posterior wall is membranous, and invaginated into the 
cylindei’, thus forming a space, the salivary chamber, between 
this wall and the outer walls of the cylinder. On this 
posterior concave wall is inserted the large pump muscle (to.), 
which extending beneath the pliaiwnx, becomes attached to 
the transverse bar of the endoskeleton. 
'Phe salivary duct leads beneath the pump, and apparently 
enters iiito the salivary chamber on its ventral surface, but I 
have not been able to definitely trace its entry into the 
chamber. Kershaw (1911) describes and figures in Prist h e- 
sancus papuensis a valvular eutrance from the salivary 
duct into the cylinder, or what this author terms the “syringe 
barrel,” but I have not observed this in Schizoneura 
lanigera. 
The working of the pump is largely controlled b}’’ the large 
pump muscle (to.). When this muscle contracts, the iuvagi- 
nated posterior wall of the cylinder is pulled outwards, and 
the cavity of the salivary chamber being enlarged, the con- 
tents of the salivary ducts are drawn into it. When the 
muscle is relaxed, the postei’ior wall of the cylinder, which is 
membranous and elastic, tends to regain its original position, 
and the lumen of the cavity being thus reduced, the saliva is 
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