HOW IS ORGANIC EVOLUTION CAUSED? 49I 



descended from one, or a few, primordial germs; and along 

 with some observable causes of modification, which he points 

 out as aiding the developmental process, he apparently 

 ascribes it, in part, to a tendency given to such germ or 

 germs when created. He suggests the possibility " that all 

 warm-blooded animals have arisen from one living filament, 

 which The Great First Cause endued with animality, with 

 the power of acquiring new parts, attended with new pro- 

 pensities, directed by irritations, sensations, volitions, and 

 associations; and thus possessing the faculty of continuing 

 to improve by its own inherent activity." In this passage 

 we see the idea to be, that evolution is pre-determined 

 by some intrinsic proclivity. "It is curious," says 



Mr. Charles Darwin, " how largely my grandfather. Dr. 

 Erasmus Darwin, anticipated the erroneous grounds of 

 opinion, and the views of Lamarck." One of the anticipa- 

 tions was this ascription of development to some inherent 

 tendency. To the " plan general de la nature, et sa marche 

 unif orme dans ses operations," Lamarck attributes " la 

 progression evidente qui existe dans la composition de 

 ^organisation des animaux ; " and " la gradation reguliere 

 qu'ils devroient offrir dans la composition de leur organ- 

 isation," he thinks is rendered irregular by secondary 

 causes. Essentially the same in kind, though some- 



what different in form, is the conception put forth in the 

 Vestiges of Creation; the author of which contends " that 

 the several series of animated beings, from the simplest and 

 oldest up to the highest and most recent, are, under the pro- 

 vidence of God, the results, first, of an impulse which has 

 been imparted to the forms of life, advancing them, in defi- 

 nite times, by generation, through grades of organization 

 terminating in the highest dicotyledons and vertebrata ; " 

 and that the progression resulting from • these impulses, is 

 modified by certain other causes. The broad contrasts be- 

 tween lower and higher forms of life, are regarded by him 

 as implying an innate aptitude to give birth to forms of 



