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THE AMERICAN NATURALIST [Vol. XL VI 



(p. 94). . . . After three years of selection of the reddest offspring no 

 appreciable increase of the red was observed except in one case, which 

 looks like a sport (p. 96). These fluctuating quantitative conditions 

 depend on variations in the point at which the ontogeny of the char- 

 acter is stopped; and the stopping point is in turn often if not usually 

 determined by external conditions which favor or restrict the ontogeny. 

 Thus the selection of redness of comb, of polydactylism. of syndactyl- 

 ism, have not proved the inheritance of quantitative variations. Ap- 

 parently, within limits, these quantitative variations have so exclusively 

 an ontogenic signification that they are not reproduced so long, at 

 least, as environmental conditions are not allowed to vary widely. 



Similarly Love 21 from experiments on the yielding 

 power of plants remarks: 



Unless further studies produce different results we can say from the 

 facts at hand that there is no evidence to show that a basis exists for 

 cumulative selection. 



Similar conclusions have been reached by Pearl 

 (1909 ) 22 in the breeding of fowls for laying purposes. 



All the above results are negative. 



Even the positive or affirmative results obtained by 

 Cuenot and later by Castle, wherein quantitative char- 

 acters may be shifted in one direction or the other by 

 selection are now given a new interpretation by certain 

 Mendelians. For example, Cuenot showed by continued 

 selection of lighter colored mice that the coat became 

 paler ; and Castle has shown that in rats the coat through 

 selection may be made darker. Castle remarks (1911) : 23 



I prefer to think with Darwin that selection . . . can heap up 

 able, and that it thus becomes creative. 



He cites cumulative results in the development of a 

 fourth toe in the hind foot of guinea-pigs and in the 

 modification of the dorsal striping of hooded rats. 



21 Love, HArry H., "Are Fluctuations Inherited?" Contr. VI, Lab. 

 Experim. Plant-Breeding, Cornell Univ., Amer. Naturalist, Vol. XLIV, 

 No. 523, July, 1910, pp. 412-423. 



28 Pearl, Baymond, "Is there a Cumulative Effect of Selection?" 



