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acters in question, or sucli are heterozygotes. It appears to the 

 reviewer that Professor Bateson's terminology is pecuh'arily fit, 

 avoiding such circumlocution as " a hybrid with fixed character," 

 meaning a homozygote, or " a hybrid with variable characters," 

 meaning a heterozygote. 



Professor Bateson speaks of two subjects, but does not dis- 

 cuss them at length, which are the theses of a paper by de Vries, 

 " On artificial atavism," namely, the resolution of compound 

 characters and the reformation of compound characters through 

 the combination of simpler ones. 



Without going into this interesting subject in detail, it can be 

 said that Professor de Vries by beautiful experiments shows that 

 characters apparently simple may be separated into more ele- 

 mental ones, and conversely by the combination of the latter the 

 compound character may be restored. In case the latter is an 

 ancestral character the phraseology "artificial atavism" is well 

 taken. 



Generally speaking, the plant breeders had not taken advantage 

 of the Mendelian theory in their work, and some of them did not 

 know of Mendel or of his experiments before the Conference. 

 As exceptions to this statement must of course be included the 

 plant breeders from the Department of Agriculture, and of these 

 notably Spillman, whose studies on wheat hybrids are well known. 

 Curiously enough, the work of Spillman was not presented at the 

 Conference. 



Although hybridization formed the theme of perhaps most of 

 the papers, not a little of the work was based on selection alone, 

 or on selection as an aid to hybridization. The experiments of 

 Orton, for instance, by which wilt-resistant varieties of cotton, 

 watermelon and cow peas were obtained, consisted merely in the 

 selection of individuals which were not subject to the disease in 

 spite of the fact that they were growing in fields where it 

 abounded. Roberts, on the other hand, succeeded in securing 

 improved varieties of wheat by a system of crossing combined 

 with rigid selection, and the same is true of other vvorkers. 



Interesting instances of the improvement of varieties by means 

 of bud selection were also given. Powell, for example, selected 



