136 Facts Compelling Us to Reject Pre formation 



side of the new animal or vice versa ; and the development 

 of the new pharynx which is found in the exact lon- 

 gitudinal axis, indicates that it can be produced indiffer- 

 ently from any part whatever of the old tissue. 108 



This remodeling of old tissues into new tissues differ- 

 ing from them indicates that the supposed determinants 

 of Weismann have not by themselves any value, for as 

 soon as the tissue finds itself in conditions different from 

 the normal ones it takes on forms and acquires properties 

 which would require determinants of quite another nature. 

 "The organism," writes Whitman, "dominates cell forma- 

 tion using for the same purpose one, several, or many 

 cells, massing its material and directing its movements 

 and shaping its organs as if cells did not exist or as if 

 they existed only in complete subordination, if I may so 

 speak, to its will." 109 And one would not know how to 

 give any better proof of the correctness of this statement 

 than that which is constituted by these particular regener- 

 ations, which utilize the material already existing to 

 remodel it into the new. 



And not only are these phenomena of peculiar regen- 

 eration irreconcilable with pre formation but the very fact 

 of regeneration in general is irreconcilable with it. 



"The germ tissue of the new organ," whites Hertwig, 

 "does not contain any remnant of the amputated organ 

 itself from which it could be reproduced by simple 

 growth. The buds destined to reconstitute the eye-bear- 



L08 E. M. Morgan : Experimental Studies on the Regeneration of 

 Planaria maculata. Arch. f. Entwicklungsmech. d. Org. Bd. VII. 

 Heft 2. and 3. Leipzig, Engelmann. Oct. 18, 1898. P. 385, 389, 395 

 -396. 



"'Whitman: The Inadequacy of the Cell-Theory of Develop- 

 ment. Biol. Lect. at the Mar. Biol. Lab. of Wood's Holl, Summer 

 Session 1893. Boston, U. S. A., Ginn 1894. P. 119. 



