THE GREAT WHITE BUTTERFLY. 151 



his history of " an animal within an animal, or 

 the Butterfly hidden in the Caterpillar." The 

 minute dissections and observations of this inde- 

 fatigable naturalist, had for their main object the 

 definite and positive proof of the natural production 

 of insects from eggs laid by parents of the same 

 species, and of the perfectly natural progression in 

 the so-called " metamorphoses" of insects ; and it is 

 not possible to conceive a more complete refutation 

 of the old theories of spontaneous generation, and 

 absolute " metamorphosis," than the richly illus- 

 trated essays which he published as the result of 

 his labours. 



The eggs of the captive Butterfly, when observed 

 under the microscope, will be found to accord pre- 

 cisely with the description given of them by Swam- 

 merdam. A tolerably strong glass will exhibit 

 the oval form with fifteen small longitudinal ridges 

 converging to the centre of the smaller extremity, 

 the spaces between them being also divided cross- 

 wise by regular grooves or channels. We may sup- 

 pose the eggs to have been deposited by the parent 

 upon the small leaves of a branch of cabbage just 

 going into flower, which should be furnished for the 

 purpose, and kept fresh by placing the stalk in one 

 of the little water bottles. 



