20 



The Journal of Heredity 



probable than others. More than this, 

 natural selection cannot mean, if 

 factors are fixed and are not changed by 

 selection." 



Most MendeHans woiild accept Dr. 

 Morgan's statement as their own. Parts 

 of it would be seriously questioned by 

 other geneticists and by many zoologists 

 and botanists and all biometricians. 

 But these parts are minor ones, and 

 the essential differences between these 

 various workers appear to be some- 

 what exaggerated by the use of differ- 

 ent names for the same thing. 



DARWIN NOT DISCREDITED 



If SO, it follows that natural selection 

 stands in almost the position where 

 Darwin left it. It is still the only ac- 

 ceptable account of how adaptation 

 takes place, unless one is content to 

 accept a mystical explanation. The 

 past half century has seen the elimina- 

 tion of many false hypotheses ; it has 



brought a clearer idea of the nature of 

 variations and a great increase in the 

 knowledge of how they are inherited; 

 but back of all this is Darwin's princi- 

 pal work — the hypothesis of natural 

 selection — which is substantially con- 

 firmed. The reviewer is unable to avoid 

 the conclusion that Dr. Morgan exag- 

 gerates the differences between the Men- 

 delian view and the original Darwinian 

 view. Fifteen years of Mendclism have 

 brought much increase of knowledge, 

 and this knowledge has made many 

 ideas of evolution clearer ; but it does not 

 seem materially to have changed the 

 theory of natural selection which Dar- 

 win built up. As far as the evidence 

 goes, we must still look on evolution as 

 due to the action of natural selection 

 on variations (or mutations), although 

 we have a much clearer idea of the nature 

 of these, and the mode of their inheri- 

 tance, than was possible to the last 

 generation. 



An Early Apostle of Seed Selection 



Seed selection is one of the methods 

 most insisted upon nowadays for the 

 improvement of the yield of maize; but 

 the principle involved is not new. The 

 Indians understood and practiced it 

 even in pre-Columbian days. A. D. 

 Shamel has called the attention of this 

 Journal to "Poor Richard's Almanack" 

 for 1812, in which Evan Evans of Wash- 

 ington, D. C, describes the "improved 

 mode" by which he secured from 1 acre 



of ground, which had not been in culti- 

 vation for twenty-five years before, 

 110 bushels of maize, besides 4 bushels 

 of beans and a quantity of turnips 

 which sold for $16. He lays the most 

 stress on the selection of proper seed, 

 and says that by choosing the largest 

 and fullest ears from the largest stalks 

 he "improved some of the corn from 

 eighteen to thirty-two rows on the 

 ear." 



Supposed Degeneration of Vegetables in the Tropics 



It is widely believed that northern 

 strains of vegetables, when planted 

 in the tropics, soon deteriorate or 

 "run out." The Porto Rico experiment 

 station has made some tests of this, 

 and reports its results in Bulletin No. 20. 

 It is true that northern vegetables 

 sometimes fail to set seed; in other 

 cases, they arc not so well adapted to 

 tropical conditions as aie the tropical 

 races; again, they may be planted at 



the wrong season; finally, the seed loses 

 viability rapidly in the moist, warm 

 atmosphere. All these factors combine 

 to foster the idea that strains of vege- 

 tables degenerate; but that such degen- 

 eration actually takes ]Dlace, does not 

 appear from the Porto Rico experiments 

 with peppers, tomatoes, beans, okra and 

 lettuce. Beans of the ninth generation 

 and okra of the eighth were in no way 

 inferior to the first generations. 



