PLATE CXII. 



PEMPniGDS spiROTHEOiE {continued). (Page 122.) 



Fig. 1. — Leaf and foot-stalk of Populus nigra. A 

 winding cavity has been formed, which is more or less 

 blistered by the sucking of the Aphides. 



Fig. 2. — The same construction viewed sideways. 

 s. The opening. 



Fig. 3. — Another example, better showing the spiral 

 contortion of the stem. By a gentle strain the foot- 

 stalk stretches and opens hke a helix, s. The opening. 



Fig. 4. — The oviparous female with her single 

 included egg. 



Fig. 5. — The non-rostrated apterous male. p. The 

 penis. 



Fig. 6. — The head and simple antenna of the ovi- 

 parous female. 



Pemphigus lactuoarius. (Page 124.) 



Fig. 7. — The nearly naked viviparous female (queen?). 



Fig. 8. — The same in a more adult form, with long 

 curls of cottony fibre. 



Fig. 9. — Head, antennae, rostrum, and eyes of fig. 8. 



Fig. 10. — Antenna of the adult form. 



Fig. 11. — Vermiform larva, possibly representing an 

 ancestral type. The point of the rostrum may be seen 

 protruding on one side. 



Fig. 12. — " Degraded" head and antennae of fig. 11, 

 with almost obsolete eyes. 



Fig. 13. — Section made through a clod of earth, and 

 thus exposing a cavity tenanted by P. lactucariiis. 

 Natural size. 



