EXPLANATION OF PLATE LXVIII. 



Fid. 1. Grape Phylloxera. — a, shows a healthy root ; i, one in which the lice are 

 woikiufir, representing the knots and swellings caused by their punctures ; c, a root 

 that has been deserted by them, and where the rootlets have commenced to decay ; 

 d, d, d, shows how the lice are found on the larger roots ; e, female pupa, dorsal view; 

 f, the same, ventral view ; g, winged female, dorsal view ; h, same, ventral view ; t, 

 magnified antenna of winged insect ; j, side view of the wingless female laying eggs 

 on roots ; fc, shows how the punctures of the lice cause the larger roots to decay. — 

 (After Riley.) 



Fig. 2. Sexual Phylloxerae. — a, female vastatrix, ventral view, showing the egg through 

 the transparent skin of the body; 6, dorsal view of the same; c, tarsus, greatly en- 

 larged ; d, shrunken anal joints as they appear after oviposition ; e, male carycBcaulis, 

 dorsal view; the dot in the circles indicates the natural size of the insect — (Alter 

 Kiley.) 



