Mr. Buckles Fallacies. 153 



ical investigation, but, still worse, in the passage 

 just quoted, he flatly contradicts a theory which 

 he elsewhere upholds. We refer to the doctrine, 

 held by many naturalists, which supposes all the 

 varieties of organic life, present and past, to have 

 arisen from one or two primitive forms, by suc- 

 cessive modifications of structure and function. 

 With the evidence which might be brought for- 

 ward in favour of this theory, we have, at pres- 

 ent, no concern. It is enough to know that Mr. 

 Buckle is himself one of its supporters, as appears 

 from several passages in his work. 1 



Now, this theory supposes that all organic be- 

 ings are continually advancing, not only in com- 

 plexity of structure and variety of function, but 

 also in the activity and vigour of their faculties. 

 This may be illustrated by comparing the ex- 

 tremes of the animal kingdom. The hydra, or 

 fresh-water polyp, is little more than a mere bag, 

 In common with all the acrita, he possesses nerv- 

 ous substance, diffused in a cellular state through- 

 out his body. 2 Moreover, if you turn him inside 



1 Vol. i. p. 806, note 130, and p. 822. The same is implied on p. 

 641. He also accepts the kindred doctrine of the unity of the organic 

 and inorganic worlds. (See vol. ii. pp. 529-533.) 



2 Or, more accurately speaking, he possesses a sensitive substance 

 which, in more elevated beings, is specialized into nervous tissue. 

 (See Lewes' Seaside Studies, p. 390.) 



