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generation at one season and of o^^parous generation at another, in the same 

 insect. I feel, however, pretty certain myself from several observations that the 

 BO-called egg3 laid in the autumn are not eggs, but immature larvae, dififenng 

 in no respect from the viviparous larvae except that they axe enveloped in a 

 covering We must consider this non-sexual reproduction, then, as analogous to 

 the gemmation of other animals as polypes generaUy, and the sexual reproduc- 

 tion to result in the impregnation of internal ova which develope then.selves 

 into larv* with a tegumentary covering within the body of the parent. These 

 are deposited by the parent on leaves and trees and have been regarded as ova ; 

 I maintain they are developed larvae with a homy case to serve as a protection 

 during the winter months. Professor Huxley believes that there is no distmc 

 tion between the ova which produce viviparous aphides and those which are 

 deposited by the perfect winged female. Is it possible that under the favourable 

 conditions of nutriment and warmth this non-sexual reproduction might be 

 continued indefinitely without any recurrence to the sexual process? And it 

 would appear that Parthenogenesis, far from being an exceptional phenomenon, 

 is a normal process in many animals. It is strikingly manifest in bees and some 

 moths. To Von Siebold, I believe, we owe this important discovery. He 

 isolated a few female moths, and placed them in boxes with glass lids. They 

 laid eggs which actually gave birth to young caterpiUars. The moths here 

 alluded to belonged to the genus Solenobice, one of the Teneidce, the larvae of 

 which family reside in a portable case. After the perfect insect appears, she 

 clings to the outside of the case or sac fiom which she has just emerged. 

 Von Siebold was particularly stiuck with the behaviour of the female Solenobiw, 

 which, he says, commence the business of oviposition very soon after exclusion ; 

 they possessed such a violent impiilse to lay their egg-, that when he removed 

 them from their sacs, they pushed their laying tube about in search of the orifice 

 of the sac, and at last let their eggs fall openly. "If I had wondered," he 

 continues, "at the zeal for oviposition in these husbandless Solenobi(S, how was 

 I astonished when aU these 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." The phenomenon of Parthtnogenesis has been described in other moths, 

 as in the silk- worm moth Bombyx mm-i, and Psyche Helix. It has been proved, 

 beyond a shadow of doubt, that the males of the hive bees are produced from 

 sexual propagation ; the impregnated eggs turn to queens and imperfect females 

 (neuters, as they are popularly called), and these larvae, as is weU known, under 

 certain conditions, might themselves become queens. Sometimes the neuters 

 lay eggs, which produce drones alone. Other animals, •as some molluscs, 

 Crustacea, and other groups of insects, besides those of which I have spoken, 

 exhibit the phenomenon of Parthenogensis. 



* The phenomenon described by the expression "alternation of ff °?I?i'°"»''' '» 

 now generaUy regarded by Naturalists aa essentiaUy one of inUmal budding, or ol 

 Ossiparous generation, which is identical with It. 



