THE r.TFE-TIISTOKY OF A LF,II'(M'TKROUS INSECT 2'Jo 



astonished when all the eggs of these females, of whose virgin state I 

 Avas most positively convinced, gave birth to yoimg caterpillars, which 

 looked about with the greatest assiduity in search of materials for tlie 

 manufacture of little cases ! " This production of fertile eggs without 

 previous copulation has also been observed in Sohnohia lichcueUa, by 

 Wocke and Keutti. Of Psyche helix, Siebold says : — " Of this extremely 

 remarkable moth we are at present only certainly acipiainted with the 

 female. In the caterpillar state it lives in a case, which in its form re- 

 sembles a sinistral snail-shell." Siebold, to convince himself of their 

 sex, made dissections of many of the wingless and almost footless moths, 

 whose unfertilised eggs, concealed in the pupa-case, developed in the 

 same year. 



In 1795, Constans de f'astellet, General Inspector of the silk industry 

 in Sardinia, reported to Reaumur that he had reared caterj)illars from un- 

 fertilised eggs of the silkworm moth. "Ex nihilo nihil tit" was Eeaumitr's 

 sliort and sceptical reply. Herold, in 183S, reported that amongst tlie 

 eggs of an unfertilised silkworm moth, some here and there passed wholly 

 or ])artially through the same changes which were observed in eggs fer- 

 tilised by true copulation, although most of the eggs remained unaltered ; 

 and the same author even distinguishes (Disquisitiones de animalium 

 verfebrin carentmm in oi:o formatione, Fasc. II., 1838, Tab. 7, fig. 31) 

 between the fcetus developed from fecundated and that developed from 

 unfecundated eggs, the former making its escape as a larva, whilst the 

 latter remained in the egg-shell and died. Herold further furnishes 

 an exact and detailed description of the changes which may be detectetl 

 with a lens, as taking place in a determinate sequence in different silk- 

 worm eggs which developed witliout fecundation. He distinguished 

 readily " various degrees of the faculty of development of unfertilised 

 eggs, which manifested tliemselves ])y infinite differences in the dis- 

 position, number, form and strength of colour, of the coloured part of 

 the egg." In some of these unfecundated eggs the faculty of develop- 

 ment had attained such a high degi'ee, that Herold " was able to 

 extract a foetus from one of them in the middle of winter." According 

 to Herold's account, embryos capable of development were not 

 found in all the unfertilised eggs which he examined, nor had he seen 

 young caterpillars creep out of unfertilised eggs, as just before the 

 period of hatching they ceased to live. It must be borne in mind, 

 however, that Malpighi as far back as 1669 (Marc. Malpiijltii Dissertafio 

 de Boiuhijce, Londini, ]i. 82), was well acquainted witli theses differences, 

 and even then knew that the eggs were not fertilised at the time of 

 copulation, but that each one was afterwards fertilised separately. 



Siebold (juotes a communication made to liim by Mons. I*. d« Filippi, 

 in 1851, to tlie effect that a celebrated Englisli entomologist, Mr. dolm 

 Curtis, when passing through Turin, had told him of an isolated chry- 

 salis of Bomhyx pob/phemus, which he had received from America, and 

 from which a female emerged, all of whose eggs developed, adding that 

 he believed the same thing happened with Bomhyx riwri, even when 

 altogether separated from males. In proof of the latter, Filij)pi stated 

 that in 1850, he observed it in that variety of the silkworm moth known 

 as trevotiui, a species having three broods in the year, that ]\Ions. Griseri 

 who was also much interested in the silk industry had found that many 

 eggs of virgin females develo})ed, and had been informed ])y uiany otlu^r 

 silkworm raisers that they had observeil the same fact. Sieliold also 



