94 
SCIENCE. 
THE WINGED PHYLLOXERA. 
J. S. Hyde, of Santa Rosa, California, a few days since, 
while examining some grape-vine roots infested with the 
phylloxera remarked to some itiends present that there 
was little danger of a rapid spread of this pest, as the 
insect, in its winged form, had not yet appeared. The 
words had scarcely passed from his lips when one of the 
gentlemen cried out : “ I see one with wings now !” 
On a more careful examination eight full-winged speci- 
mens were found ; the next day four other specimens 
were discovered. Several of these insects were sent 
to Dr. Hilgard of the State University for examination. 
The above announcement by Dr. Hyde is very 
interesting, and not the less so from the fact that the 
insects he sent to Prof. Hilgard, although truly a winged 
form, were sterile, and not capable of spreading the 
destruction which our vine-growers fear. In order to 
Fig. i. 
Fig. 2. 
show the difference between the fertile and infertile 
winged-forms, we have reproduced engravings from 
Prof. Riley’s drawings of the phylloxera which show 
clearly the distinction between the two. Fig. i is the 
fertile winged female, which thus far has not been 
observed in this State, unless some of the insects 
retained by Dr. Hyde are of this form. Fig. 2 shows 
the outline of each of the five specimens received by 
Prof. Hilgard. It will be observed that in the fertile 
winged female the abdomen is prolonged and that the 
body is about half as long as the whole insect, wings 
included, and is of a tapering, rounded form. In the 
sterile, the body is rarely one-third the length of the 
whole insect, and the abdomen is abruptly contracted, 
as shown in the engraving. 
Concerning the finding of the sterile winged form by 
Dr. Hyde, Prof. Hilgard spake at the meeting of the Hor- 
ticultural Society as follows: “ After all the matter still 
rests pretty much as we conjectured two years ago. I 
lhen stated that either the winged phylloxera was not 
here at all, or in very small numbers. There are five or 
six varieties of the insect non-winged, which live on the 
roots, and which produce a winged form towards autumn, 
which, like the wingless form, is simply a female which 
lays eggs without any connection on the part of the male. 
The winged female is simply an egg-layer, like the others. 
She lays a few eggs only. Some of these eggs produce 
males and others females. It seems to be necessary that 
there should be a kind of renovation of the race in that 
way. The winged insect is dangerous, of course, because 
it is capable of flying to some extent. In Europ? the 
winged form has been known to traverse a distance of 30 
or 40 miles at one jump, leaving districts between unaf- 
fected. In Sonoma the progress of the pest has been 
slow, and it has been thought that the winged insect was 
absent. The winged forms produce only two varieties-- 
one fertile, the other infertile. I understand that in othei 
countries the proportion of infertile insects is small. Of 
the eight specimens sent me by Dr. Hyde, I find that five 
are of the infertile kind. I infer, therefore, from the evi- 
dence thus far produced, that the spread of the pest will 
still be comparatively slow, depending upon the kinds 
that crawl instead of those that fly.” 
The announcement of Dr. Hyde, which was made to 
the Rural Press, will doubtless induce a still wider search 
for the winged insect. We shall be pleased to receive any 
specimens which may come to the eyes of our readers to 
determine their exact standing. 
INSTANTANEOUS PHOTOGRAPHY IN A BAL- 
LOON. 
Paul Demarets. 
Since the memorable day when the bold Pilatre de 
Rozier and the Marquis d’Arlandes left the earth for the 
first time, up to the present, all aerial travelers have been 
struck with the clearness with which the celestial land- 
scapes have opened up to their view. The idea of em- 
ploying photography to fix these admirable contours is 
contemporaneous, so to speak, with the invention of 
Niepce and Daguerre. 
To M. Nadar belongs the credit of making the first 
attempts, and to M. Dagon the merit of remarkable exe- 
cution in bringing the ascensions under control. But in 
spite of these successes, thanks to the generous aerial 
hospitality of M. Henry Giffard, one would think that the 
fixation, at a distance, of celestial landscapes upon a 
sensitized plate in a balloon, was a mere chimera. In 
fact the rapidity of the motion of the aerostatic globe, and 
the rotation about its axis, would seem insurmountable 
obstacles. 
Attention has been recently directed to the rapidity of 
impression which may be attained, and which I believe I 
have increased by the aid of certain re-agents ; but one 
difficulty still to be surmounted was the want of some 
means by which the operculum could be closed with such 
rapidity that the operation would take only a fraction of a 
second. 
The readers of L' Electriciti know how M. Stein, the 
able experimentalist of Frankfort, sought for a solution 
of this problem. It has also described the ingenious 
apparatus which M. Janssen has made use of in his 
observatory at Mendon, by which he has secured 
great rapidity of action on burning a thread of silk which 
held the mechanism in position. But it was impossible 
to use this apparatus in an aerostat, although admirably 
adapted to observation from a fixed position. I should, 
therefore, have been unable to employ this method if the 
idea had not occurred to me of using electricity by the 
aid of the mechanism I am about to describe. 
I take a ring, in the centre of which my objective is 
fixed, normally and solidly, and for the sake of illustra- 
tion, we shall suppose it to be horizontal. A spring, at- 
tached to an arc, situated at the centre and parallel with 
the objective, presses a horizontal plate, parallel with the 
ring of the base. This plate bears a shoulder which 
rests upon a vertical piece of iron. This has a vertical 
