64 THE ENTOMOLOGIST. 



while others, becoming more elongate, quit the earth as 

 pupa-nyraphs, furnished with rudimentary alary appendages, 

 emerging in the winged state from July to September. But 

 the development of the race does not terminate here, on 

 attaining the winged condition. In an interesting memoir, 

 *Sur le Phylloxera aile et sa progeniture,' M. Balbiani has 

 shown that these winged females (to which no males are 

 ascribed) deposit their eggs, two to five in. number, amid 

 the down of the young vine-leaves, when in captivity ; from 

 which eggs an apterous sexual race is derived, as previously 

 described by him (in 1873) in the case of the Phylloxera of 

 the oak (P. Quercus of Fonscolombe), these eggs being of two 

 different dimensions, the larger producing females, and the 

 smaller males, both sexes destitute of organs of nutrition, 

 the promuscis being reduced to a short flattened tubercle, 

 and the female having the third joint of the antennae 

 pedunculated. The same diligent observer has more recently 

 ascertained that the subterranean brood of the Phylloxera of 

 the vine is also continued from year to year by a similar 

 sexual race, which appears later than that derived from the 

 winged type (about the middle of October), but perfectly 

 identical therewith, the females of both producing only a 

 single egg '^^ ceuf dliiver of Balbiani) ; whereby, in the one 

 case, the continuity of the race is maintained for several 

 years upon the same root until this is entirely exhausted ; 

 while, in the other, by the intervention of the winged type, 

 new colonies are dispersed far and wide. M. Balbiani also 

 states that certain abnormal forms, occasionally found mingled 

 with the winged type, noticed by him in several other species 

 and formerly considered as males, are rather to be regarded 

 as females with atrophied characters, somewhat analogous to 

 the neuters of social Hymenoptera. Some strange theories, 

 however, have been propounded by M. Lichtenstein, as to 

 certain phases in the genetic cycle of the race, whereby it is 

 alleged that the winged Phylloxera of the vines resort to the 

 Kermes oak (Quercus coccifera) to deposit — not eggs, but 

 — pupcB, from which such sexual race is developed as 

 aforesaid; this winged type being characterized as "Andro- 

 phores" and " Gynephores," according to the sex of the 

 pupcB deposited by these so-called "flying cocoons." 

 M. Balbiani, however (on examining other specimens taken 



