38 
THE ENTOMOLOGIST’S WEEKLY INTELLIGENCER. 
use of the lateral opening in the hinder 
whorls of the case, although the animal 
with its empty, shrivelled body could 
easily force its way out, through the 
narrow aperture at the apex of the case. 
But there is probably another circum- 
stance w'hich prompts the caterpillar in- 
stinctively, whilst finishing and enlarging 
its case, to introduce a lateral opening 
below the uppermost narrow whorl ; I 
mean the eventual permission of the act 
of copulation, which, in this case, from 
the peculiar form of the case, could only 
be effected through a low lateral aperture 
of this kind.” 
This case-bearer was first mentioned 
by Reaumur, who has figured the case, 
but for many years it had escaped atten- 
tion, till recently (in 1849) Senator Von 
Heyden observed it near Freiburg, and 
it has subsequently been found in many 
other localities, and on the Continent it 
appears widely distributed, but we are 
not aware of any British specimens 
having been found. We think we hear 
some reader exclaim, “Tell us what it 
feeds on !” to this we reply in the words 
of Professor Von Siebold : — 
“ The caterpillar of Psyche Helix 
selects various plants for its nourishment. 
On the Schlossberg, near Freiburg, it 
feeds upon Artemisia vulgaris. According 
to Zeller’s testimony, it also lives upon 
Anthyllis vulneraria, Lotus corniculatus 
and Gnaphalium arenarium. Kollar found 
his on A triplex laciniata.” It has also 
been found on “ Alyssum montanum , 
Teucrium Chamadrys, Cheiranthus odo- 
ratus and Scabiosa arvensis ,” and has 
been fed with “ Lamium purpureum and 
Hippocrepis comosa.” 
“ These case-bearers are leaf-miners, 
after the fashion of the caterpillars of 
Coleophora , pushing their bodies far in 
between the cuticles of the leaves, through 
a round hole which they gnaw in the 
latter, and devouring the chlorophyll all 
round them, during which process the 
case remains outside, sticking with its 
aperture to the opening in the epidermis. 
The leaves and even the variegated 
flowers of the food-plants are often in this 
way completely decolorized by the case- 
bearers.” * * * * “ When these case- 
bearers are full-grown, which is the case 
in the latter part of the summer, they 
quit their food-plants, like the other 
caterpillars of the Psychidce, and seek a 
suitable place for their change to the 
pupa-state. When they find stone walls 
or rocks in their vicinity they creep high 
up on them, and spin down the lower 
aperture of their dwelling firmly. In 
passing through the process of moulting 
also, these caterpillars, like all other case- 
bearers, always spin down their habita- 
tions temporarily.” 
This last-mentioned circumstance has 
been sometimes curiously misunderstood, 
and in Kirby and Spence we find it thus 
cited: — “The caterpillar of a little moth 
knows how to imitate the air-pump, pro- 
ducing a vacuum when necessary for its 
purposes, without any piston beside its 
own body.” (Seventh edition, pp. 8 and 
261). We are sorry to destroy any of the 
romance with which these insects have 
been invested, but truth compels us to 
assert that the firm adhesion of a case to 
a leaf is never caused by a vacuum pro- 
duced by the tenant inside ; the cases are 
much too large ever to be completely 
filled by the body of the caterpillar, and 
the firmer adhesion in some cases is 
caused by the case being purposely more 
securely spun to the surface on which it 
rests, whilst the larva retires to change its 
skin ; the proceeding being analogous to 
that of a human being, who, while in the 
operation of dressing, should fasten his 
door. 
Professor Von Siebold continues: — 
“If, after some time, we examine the 
spun-down case of a Psyche Helix during 
its period of pupation, we find the pupa 
in the lower whorl of the case, with its 
anterior extremity directed upwards, and 
its hinder extremity downwards towards 
