166 PTILOTA. 



Herold meant not to imply any power independent of the 

 Creator, but simply that principle of developement which, 

 under the guidance of an Almighty hand, is constantly in 

 operation, not only in insects, but in every other branch of 

 the creation.* 



But, in the next place, Messrs. Kirby and Spence do not 

 deny the facts stated by Dr. Herold, that the organs of the 

 butterfly are not discernible in the larva, but gradually be- 

 come visible as the caterpillar throws off its successive cover- 

 ings. They assert, indeed, that they can easily comprehend 

 that pre-existent germes, by the constant secretion of new 

 matter, in a proper state, may be gradually developed ; but 

 find it impossible to conceive how, by the action of second 

 causes, without the mtervention of the First Cause, the Sw^^er- 

 f,y should he formed in the caterpillar, unless it pre-exists 

 there as a germe or foetus. The question is not, however, 

 whether the butterfly be or be not inclosed as a fcetus mthin 

 the caterpillar, but whether, as Swammerdam evidently in- 

 tended, the various skins of the caterpillar, &c., existed as 

 distinct and visible germes within the newly-hatched cater- 

 pillar; and this Messrs. Kirby and Spence endeavour to 

 support by the argument which they adduce from Bonnet, 

 that " organs that have no existence as to us, exist as they 

 respect the embryo, and perform their essential functions ; 

 the term of their becoming \^sible is that which has been 

 erroneously mistaken for the period of their existence." 



The question, therefore, now assumes a new form. It is 

 not, as between Swammerdam (contending that the succes- 

 sive skins of the caterpillar exist as distinct and visible 



* It is rather remarkable, that Messrs. Kirby and Spence, after having 

 thus endeavoured to brand Dr. Herold as an atheist, should have ex- 

 pressed a supposition that the skins of serpents are formed under the old 

 skin, from the rete mucosum (vol. iii. p. 191). The vis formatrix of Dr. 

 Herold is of no higher rank than the power implied in this expression. 



