612 TEXT-BOOK OF ENTOMOLOGY 



silkworm, perceiving that before pupation the antennae are concealed 

 in the head of the larva, where they occupj r the place previously 

 taken by the inandibular muscles ; also that the legs of the moth 

 grew in those of the larva, and that the wings developed from the 

 sides of the worm. 



Even Reaumur (1734) remarked : " Les parties du papillon. 

 cachees sous le fourreau de chenille sont d'autant plus faciles a 

 trouver que la transformation est plus proche. Elles y sont nean- 

 inoins de tout temps." He also believed in the simultaneous exist- 

 ence of two distinct beings in the insect. "II serait tres curieux de 

 connaitre toutes les communications intimes qui sont entre la chenille 

 et le papillon. ... La chenille hache, broye, digere les aliments 

 qu'elle distribue au papillon ; comme les meres preparent ceux qui 

 sont portes aux fostus. Notre chenille en un mot est destinee a 

 nourrir et a defendre le papillon qu'elle renferme." (T. i, 8 e Me- 

 moire, p. 363.) 



Lyonet (1760), even, did not expose the error of this view that 

 the larva enveloped the pupa and imago, and, as Gonin says, it was 

 undoubtedly because he did not use for his dissections of the cater- 

 pillar of Cossus any specimens about to pupate. Yet he detected 

 the wing-germs and those of the legs, stating that he presumed the 

 bodies he saw to be the rudiments of the legs of the moth (p. 450). 



Herold, in his work on the development of the butterfly (1815), 

 was the first to object to this erroneous theory, showing that the 

 wings did not become visible until the very end of larval life; that 

 as the larval organs disappear, they are transformed or are replaced 

 by entirely new organs, which is not reconcilable with a simple put- 

 ting off of the outer envelope. The whole secret of metamorphosis, 

 in Herold's opinion, consisted in this fact, that the butterfly in the 

 larva state increases and accumulates a supply of fat until it has 

 reached the volume of the perfect state ; then it begins the chrysalis 

 period, during which the organs are developed and take their definite 

 form. 1 (Abstract mostly from Gonin.) Still the old ideas prevailed, 



1 We copy from Kirby and Spence their abstract of Herold's conclusions: "The 

 successive skins of the caterpillar, the pupa-case, the future butterfly, and its parts 

 or organs, except those of sex, which he discovered in the Tiewly excluded larva, do 

 not preexist as germs, but are formed successively from the rete ))iui-t>xnni, which 

 itself is formed anew upon every change of skin, from what he denominates the blood, 

 or the chyle after it has passed through the pores of the intestinal canal into the 

 general cavity of the body, where, being oxygenated by the air-vessels, it performs 

 the nutritive functions of blood. He attributes these formations to a vits forma trijr 

 (bildende Kraft). 



"The caul or epiploon (fett-nutRsc), the corps t/raisseux of Re'aumur, etc., which 

 lie supposes to be formed from the superfluous blood, he allows, with most physiolo- 

 gists, to be stored up in the larva, that in the pupa state it may serve for the devel- 



