﻿NORTH AMERICAN SPHINGID^E. 103 



the sustenance of life. For, if this be not true, what significance can we assign to 

 the harmony and intelligent design, everywhere characterizing the relationships of 

 organic nature? The natural history of the earth teaches us to believe, that physical 

 influences were established antecedent to the creation of organic bodies, and we know 

 that vegetable forms, being producers or creators from the simple elements of the 

 material for the sustenance of the animal, must likewise have been its precursor, and 

 we must look for adaptability in the latter to the conditions under which it was to 

 pass its life, and not that it is capable of being indefinitely molded, modified and 

 controlled by the existence of agencies and conditions, which had fully recognized 

 and established existence, previously to its appearance upon the earth. I know, as 

 well as any one, there is nothing like positive organic immobility or fixity in the 

 animal organism ; that it is a scene of constant, perpetual fluctuation ; that the con- 

 dition of life is one of change, waste and renovation throughout its continuance, but 

 under an immutable and predetermined plan, comprehending a certain degree of 

 adaptiveness, by which it is accommodated to the unequal action of the conditions 

 under which it may exist. Within this limit the operation of organic processes are 

 evidently, one may say eminently, influenced by physical agencies. Cold depresses 

 and retards their action and development ; heat stimulates and advances, and the 

 animal being incapable of generating or creating a single element of the simplest of 

 its constituents, but assimilating those already prepared for its use by other organisms, 

 scarcity or abundance of food likewise affect it. And though this more than either 

 the influences mentioned may produce physical degeneration, yet even combined with 

 the external agents is there a single fact in physiological science which justifies the 

 belief, that they influence cell development in any other manner, save that of disease, 

 leading not only to the extermination of the individual, but of its progeny ? Con- 

 template the climatal changes, and the altered facilities of obtaining sustenance as 

 taking place almost insensibly, and extending their range of effects into geological 

 periods, adding isolation to intensify their influence, and where must permanent 

 variation of species, or the tendency to change indefinitely, have its inception? 

 Beyond doubt, as the advocates of the latter doctrine especially claim, in the cell-action 

 of the reproductive system. If this is capable of undergoing any other change than that 

 which produces monstrosities, organisms are thus successively and insensibly altered 

 by almost imperceptible modifications, until in the course of ages nothing remains to 

 them that was originally specific, and, by parity of reasoning, nothing that was generic, 

 or tribal, or ordinal, or pertaining to classes. Thus, when it is once admitted that 

 modification may take place in any organ or part essential in specific life, there is no 

 limit to what may take place under the supposed operation of physical influences. 

 All closely allied forms cease to be the objects of special design ; special creation itself 

 becomes problematical, since under this view, the primitive germs themselves may have 



