160 TRANSFORMATIONS OF INSECTS. 
the rudiments of a mouth are found, and of two eyes without facets. 
The movements of these admirable examples of retrograde meta- 
morphosis—and how slightly they resemble the well-developed 
Lepidoptera !—are extremely sluggish, and the six little feet of the 
thoracic segments, which are in the form of very short conical 
processes, scarcely take any part in them. A dissection proved 
these moths to be true females. They deposited their yellowish 
eggs in the empty pupa case which in Psyche always remains 
behind in the caterpillar sac; they then shrivelled up to a very 
small volume, when they generally left the sac by the above- 
mentioned side aperture, and soon afterwards died.” Von Siebold 
proceeds in the description of this strange case as follows :—“ The 
unfertilised eggs concealed in the pupa case are also developed in 
the same year. If a spun-down sac of Psyche helix be opened in 
the latter part of the autumn, or in winter, we always find from ten 
to twenty-four young reddish-grey caterpillars in the interior of the 
pupa case.” No other method of reproduction but by virgin 
females, and without the influence of the male, was witnessed in 
this Psyche by Von Siebold. 
Heroldt described the changes which go on in the young silk- 
worm within the eggs laid by unfertilised female moths, and found 
that development proceeded all the same; and Von Siebold 
acknowledges that the silkworm can be raised occasionally from 
unfecundated eggs. 
Other observers have decided that the tiger and other moths 
can be thus reproduced, but the above instances must suffice to 
show the extraordinary method of reproduction amongst the 
Lepidoptera, which is of such great importance amongst the bee 
tribe. 
The alterations in the external structures of some genera 
during successive moultings of the skin have been pointed out. 
Thus in Hadena oleracea, the caterpillar has different colours 
when old to those which ornamented it during the early part 
of its life, and the “Forked Tail” undergoes alterations in 
colour during the skin casting process. A¢tacus cecropie@ submits 
to corresponding changes in its tints. It is thus necessary to 
consider the moulting periods as most important epochs in the 
evolution of the Lepidoptera, although the marked stages of meta- 
