i 5 8 
TRANSFORMATIONS OF INSECTS. 
Tineina have that power of reproduction which dispenses with 
the male for many generations. The maiden females of Solenobia 
lay eggs which are fertile, and a succession of broods may occur 
without a male ever being seen. This method is sometimes 
called “ parthenogenesis.” 
The celebrated German naturalist, Von Siebold, examined into 
this question, and his work was translated by W. S. Dallas, in 
1857. Von Siebold collected a great number of the cases, or 
sacs, as he calls them, of Solenobia lichenella and Solenobia trique- 
trella , and to his great astonishment none but female individuals 
came out of them, and only a single locality furnished him with a 
couple of males. He kept these females carefully in little vessels 
closed with glass lids, and found that they clung to their cases, 
resting upon the outside of them. These virgin females laid eggs 
and filled their sacs with them, and did not wait for any fertilising 
male, for they commenced egg-laying very soon after they escaped 
from the pupa case, or the chrysalis condition. When the 
Solenobice were removed from their sacs, they had such a violent 
impulse to lay, that they pushed their laying-tube about in search 
of the surface of the sac, and at last let their eggs fall openly. 
He writes : “If I had wondered at the zeal for oviposition in 
these husbandless Solenobice , how was I astonished when all 
the eggs of these females, of whose virgin state I was most 
positively convinced, gave birth to young caterpillars, which 
looked about with the greatest assiduity in search of materials for 
the manufacture of little sacs.” He thought that this egg-laying 
might be a similar phenomena to that of the birth of successive 
generations of Aphides from the internal budding of sexless indi- 
viduals ; but on examining several of the Solenobice , they proved to 
be perfectly-developed females. A similar laying of fertile eggs 
by a virgin of the species Psyche helix is noticed and carefully 
explained by Von Siebold. He states : “ The two species of sac- 
bearers just mentioned are not, however, the only representatives 
of the true parthenogenesis ; an equally striking example of the 
virgin reproduction of a female insect is presented by Psyche 
helix. Of this remarkable moth we are at present only certainly 
acquainted with the female. In the caterpillar state it lives in a 
sac which in its form resembles a sinistral (turning to the left) 
