Department of Plant-Breeding Ixix 



such as erect or horizontal branching, large or small branches, has been 

 carefully considered, and it seems that these characters evidently behave 

 in a Mendelian manner. 



Another interesting observation in connection with these experiments 

 is the fact that in the third generation of these hybrids many types show- 

 ing intermediate sizes and forms of fruit are apparently reproducing these 

 intermediate forms true, while by the law of segregation they would be 

 expected to split into the two parental types. The explanation of this 

 phenomenon has not yet been found. 



A preliminary paper on these experiments has been published and a 

 detailed report of the results of the experiments will be issued as soon 

 as possible. 



Other Mendelian studies are being made with oats, radishes, browallias, 

 morning-glories, and the like, and many data of interest are being 

 accumulated. 



Studies on mutations and their use in breeding. — It is obvious that the 

 investigations of mutations must be closely associated with the studies of 

 variations, as at present we know very little regarding the causes of 

 mutations. Among the most important studies of this nature under way 

 are those connected with the timothy-breeding work and the study of 

 variations in the daisy. The striking variations that have been found in 

 timothy, some of which have formed the basis of valuable new varieties, 

 are apparently to be classed as mutations, and careful studies of them are 

 being made to determine what they are. In the timothy work all types 

 of variations are being isolated and studied regardless of their value in 

 order to obtain, if possible, some idea of the nature of the variations. In 

 any case this study will furnish an extended analysis of the characters 

 of timothy and of their combination in different races now existing but 

 mixed indiscriminately in what we know merely as timothy. 



A large number of strikingly different types, which are probably to 

 be considered as mutations, have been found to exist in the wild daisy. 

 These have been isolated and plantings made from them. Careful notes 

 are being taken and further plantings made in order to determine 

 whether these different types reproduce their characters as mutations 

 should do, or whether they are merely environmental variations. 



Studies on the cumulative action of selection. — The studies on this 

 subject, which are mainly with wheat and oats, are being continued, but as 

 yet there are no results available for publication. Experiments of this 

 nature must be conducted for many generations before any conclusions 

 may be drawn. 



Correlation of characters. — One of the very important problems in 

 breeding is to know the interrelations of characters, or the correlation of 



