THE THEORY OP EVOLUTION FOUNDED IN NATURE. 153 



in the back-ground the idea of a personal Creator; but minds no 

 less devout, and perhaps a trifle more thoughtful, see the hand 

 of a Creator not less in the evolution of plants and animals from 

 preexistent forms, through natural laws, than in the evolution 

 of a summer's shower, through the laws discovered by the 

 meteorologist, who looks back through myriads of ages to the 

 causes that led to the distribution of mountain chains, ocean 

 currents and trade winds, which combine to produce the neces- 

 sary conditions i-esulting in that shower. 



Indeed, to the student of nature, the evolution theory in biol- 

 ogy, with the nebular hypothesis, and the grand law in physics 

 of the correlation of forces, all interdependent, and revealing 

 to us the mode in which the Creator of the Universe works 

 in the world of matter, together form an immeasurably grander 

 conception of the order of creation and its Ordainer, than was 

 possible for us to form befoi'e these laws were discovered and 

 put to practical use. We may be allowed, then, in a reverent 

 spirit of inquiry, to attempt to trace the ancestry of the insects, 

 and without arriving, perhaps, at any certain result, for it is 

 largely a matter of speculation, point out certain facts, the 

 thouglitful consideration of which may throw light on this 

 diflicult and embarrassing question. 



Without much doubt the Poduras are the lowest of the six- 

 footed insects. They are more embryonic in their appearance 

 than others, as seen in the large size of the head compared with 

 the rest of the body, the large, clumsy legs, and the equality in 

 the size of the several segments composing the body. In other 

 characters, such as the want of compound eyes, the absence of 

 wings, the absence of a complete ovipositor, and the octasional 

 want of tracheae, they stand at the base of the insect series. That 

 they are true insects, however, we endeavored to show in the pre- 

 vious chapter, and that they are neuropterous, we think Is most 

 probable, since not only in the structure of the insect after birth 

 do they agree with the larvfc of certain neuropters, but, as we 

 have shown in another place * in comparing the development of 

 Isotoma, a Poduran, with that of a species of Caddis fly, the 

 correspondence throughout the diff"erent embryological stages, 

 nearly up to tlie time of hatching, is very striking. And it is a 



♦Memoirs of the Peabody Academy of Science, II. Embryological Studies on 

 Diplax, Perltliemis, and tlie Tliysanurus genus Isotoma. Salem, 1871. 



