GRAPE DISEASE. 535 
Mountains, has not yet crossed to the other side. If such is the 
case, our California neighbors should take warning from Europe, 
and guard, if possible, against an invasion. 
The announcement that I have at last ascertained one of the 
principal causes, if not .the sole cause, of this decline, and 
that, knowing the cause, we may in a measure obviate it, wil 
= doubtless cause many a grape-grower to wonder. Some may even 
= pooh-pooh the idea, and deem it impossible that they have so long 
~ ‘temained in ignorance of so important a fact, that a‘ bug-hunter ” 
should discover it at last. Let the facts speak.* 
This destructive agent 1s none other than the little insect we 
are now treating of. 
The general history of the louse, and. the habits of the gall- 
inhabiting type were sketched in my last Report, and need not be 
i repeated. 
s FURTHER PROOF OF THE [IDENTITY OF THE AMERICAN Insect 
_ WIH THe European.— That the two are identical there can no 
co longer be any shadow of a doubt. I have critically examined the 
living lice in the fields of France, and brought with me, from that 
country, both winged male and female specimens, preserved in 
acetic acid. I find that the insect has exactly the same habits 
here as there, and that winged specimens which I bred last fall 
from the roots of our vines, accord perfectly with those brought 
over with me. In the different forms the insects assume, in their 
Work, and in all other minutia, the two agree. 
HY I CONSIDER THE ĢGALL-LOUSE AND ROOT-LOUSE IDENTICAL. 
— First, wherever this insect has been noticed in England, both 
the gall-inhabiting and root-inhabiting types have been found. 
In France, the galls occur abundantly on such of our American 
et 
i is really amusing to witness how the facts here set forth have been received b 
who n I Metini pereo por bject in their lives. In the silk- 
Worm disease that has of late years been so prevalent in Europe, M. Pasteur, after the 
ed instaking and elaborate experiments, at which he sacrificed his health, unrav- 
yateries, gave to the world the true pathology of pebrine, and what is more, 
er: a e 
Were very slow to believe the hard, dry facts which had been snatched from 
s Toa AA 
were inclined to 
i iiini Co" as something mysterious — something altogether beyond man’s 
fit “ng, and consequently uncontrollable. The most ignorant are always the 
tos dag call I might mention several parties who have expressed their opinion 
simply p rere has no connection with di or decline in the Vine. To such, I 
ety BAY: exam ASS ini m I might 
E a a ae EE Me a Cane aaor, che 
8ay: read t, — reason chaps a A 
q 
imilar opinion in my mouth. To these last, I 
by no means jump to conclusions! 
