DISPERSION OF GIPSY-MOTH LARVJE BY THE WIND. 3 
FORMER INVESTIGATIONS OF HAIRS ON SMALL LARV7E, 
The bodies of first-stage larvae (PI. I, fig. 1) are provided both 
dorsally and laterally with two types of hairs, or setae, namely, short, 
smooth hairs bearing a vesicle about the middle and very long, slender 
ones which are covered with spinules. Wachtl and Kornauth in 
J 1893 first described the aerostatic setae found on the first-stage 
larvse of P. disbar L. and Lyrnantria monacha L. and designated 
the balloon-shaped swellings occurring on these setae as aerophores. 
They suggest that these aerophores assist in the dissemination of the 
young caterpillars through the air. 
Prof. Cholodkovsky in 1894 made some investigations and found 
that the swellings or vesicles shrank in dead larvae. His discovery 
tended to weaken the theory that these swellings contain air and to 
suggest that they may contain a fluid which will naturally dry up 
after death. He also found that the swellings remained for months 
in alcohol as full and rounded as in living larvae, and if the preparation 
was allowed to dry on a slide the aerophores quickly shriveled. 
He therefore concluded that they did not contain air but a fluid 
which was probably poisonous and served as a protection against 
insectivorous birds. 
Igenitzky, a student of Cholodkovsky, in 1897 further studied the 
glands that give rise to the hairs and verified the findings of the former 
investigator, who proposed to call the swellings "toxophores. v He 
further states that the role of rendering the larvae more buoyant may 
better be ascribed to the long thin hairs which resemble the pappus 
of some plant seeds. 
Prof. K. Escherich in 1912 published a resume of former investiga- 
tions into the function of the hairs and cites later work by Wachtl and 
Kornauth in 1907 in which they cling to their former theory of aero- 
phores. The latter found that the vesicles did not contain liquid, as 
no reaction was noted by immersion in litmus, rosolic acid, or phenoi- 
phthalein, indicating that they contained neither alkali nor acid. 
They did not shrink in alcohol, glycerin, or acetic acid, or excite any 
capillary action; hence the investigators concluded that nothing but 
air could be contained in them. Prof. Escherich lays stress on the 
air refraction noted in connection with these balloons when immersed 
in glycerin and viewed under the microscope. 
T. C. Shcherbakov in 1914 published observations on the gipsy 
f moth in which he deals at length with the function of the hairs on the 
first and second stage larvae, and parts of his paper have been trans- 
lated by Mr. J. Kotinsky of the Bureau of Entomology. Shcher- 
bakov says that the aerophores are not filled with air or gas and that 
their connection with the glandular cells would indicate that these 
vesicles are probably filled with a poisonous secretion. Their exceed- 
