270 
THE FLOEIST AND POMOLOGIST. 
[ Droember, 
are produced females without wings, and equally males without wings from the male 
eggs. They are incapable of feeding, for neither has a sucker. From these males and 
females proceed a fresh laying of eggs, or rather of egg, for the female only lays one 
solitary egg, which is not yellow, but more or less of a sombre green, and is very difficult 
to perceive on the bark, where it is fixed by a small hook. It passes the winter thus 
and in spring a wingless individual is hatched exactly resembling those on the roots, but 
with a very long sucker. This vernal individual is very fertile, containing from twenty to 
twenty-four ovaries or reservoirs full of eggs. Its descendants produce eggs without the 
intervention of males, some of them fixing themselves on the leaves and producing galls, 
the others reaching the roots and renewing the subterranean race. How long the race 
may be propagated in this way, without the intervention of the sexual males and females 
above spoken of, is not known. But as the continual renewal of the race proceeds, each 
Fig. 4.—-Vine Leaf infested with Phylloxera. 
brood becomes less and less fertile, by a reduction in the number of the egg-bearing tubes 
or ovarian reservoirs. The winged female, fertile without the intervention of a male, only 
lays a small number of eggs—from four to ten. At last the progress ends by the sexual 
female having no more than a single ovarian reservoir and a single egg, which will be 
sterile if there is no male to fertilise it. In this way the single egg which terminates the 
Phylloxerian cycle is reached. 
“ The above is the account now given by Professor Balbiani and Professor Maurice 
Girard of the evolution of the Phylloxera. Whether their views are well founded or not 
remains to be seen. They are the authors who have paid most attention to the subject, 
and to whose opinion much weight is attached. Their solution of the problem how to 
destroy the Phylloxera is to kill the winter egg deposited on the cane by smearing the 
