RECAPITULATION 333 



variations, have been almost infinite, and that, there- 

 fore, this explanation of the preservation of varia- 

 tions cannot be correct. 



I have claimed that isolation by barriers cannot 

 account for the preservation of new varieties, for the 

 reason that it is just as difficult to account for the 

 preservation of a variety when formed from part of 

 a species as when formed from the whole species. 



I have enumerated the several things which must 

 occur simultaneously before cross-sterility between 

 parent and offspring could occur and become effective, 

 namely, that a number of individuals must be born at 

 the same time possessing the same variation, that the 

 variation must be useful, that these individuals must 

 be fertile with each other, that they must be cross- 

 sterile with the parent form, and that, [finally, the 

 few, if any, individuals thus produced and being 

 widely scattered through the species, must find each 

 other before they could propagate. I regard it im- 

 possible that these things could all occur simultane- 

 ously. 



I have quoted from Mr. Spencer, showing that 

 " either there has been inheritance of acquired char- 

 acters, or there has been no evolution." He admits, 

 however, that there are but few known facts which 

 go to support his theory. It is evident that the diffi- 

 culties of preserving and propagating an acquired 

 character are those already pointed out. I see no 

 reason why acquired characters would not, in a state 

 of nature, be speedily merged. 



The lack of harmony in the teaching of evolution- 

 ists shows that there is much vagueness as to the 

 details of the theory. 



I next called attention to the difficulties arising 

 from paleontology. The theory of evolution must 

 assume that the first half of the history of life is en- 



