26 Department of Experimental Plant-Breeding. 



problems of considerable scientific interest is the study of the varia- 

 tions. Timothy has been cultivated for many years yet practically no 

 attempt has been made to separate out distinct varieties or races. A 

 study of the numerous individuals in our experimental plats shows 

 that very great differentiation has taken place. Numerous individuals 

 can be found exhibiting striking characteristics which are probably 

 to be considered as mutations in the De Vriesian sense, representing 

 elementary species or biotypes. These types are distinguished by 

 difference in height, color, arrangement of leaves, breadth of leaves, 

 size and shape of head and numerous other differentiating characters, 

 and are remarkable for their extent and diversity. A careful study of 

 these variations is being made with the view of determining their true 

 nature. Plats are being grown from self-fertilized seed of over a 

 hundred different types, and in many instances these are being grown 

 in comparison with similar plats planted from open-fertilized seed 

 and from slips or vegetative parts in order to determine the extent of 

 variation under different methods of propagation. 



Very extensive data has been accumulated during the experiments, 

 which will give material for a careful statistical study of the range 

 of variation and the preparation of correlation tables. As an illustra- 

 tion of the extent of this data it may be stated that the notes taken 

 for five years annually on over 8,000 plants include weight of product 

 or yield, height, date of beginning of bloom, date of close of bloom, 

 and season of maturing. This study should furnish further informa- 

 tion of importance on the nature and range of variation, than which 

 in breeding there is no more important problem. It should show the 

 length of life of timothy and the ranqe of variation in this character 

 which has already been found to be very great. It should determine 

 what variations occur that are important in a superior timothy variety 

 and whether these variations can be perpetuated. 



Production of improved varieties. — The studies which have been 

 made of the variations have shown that we have the foundation varia- 

 tions for manv important improvements, and would indicate that our 

 agriculture would gain very much bv the introduction of special-pur- 

 pose varieties. The individuals which for the first two vears gave the 

 heaviest yields and which for this reason were selected and propa- 

 gated were in the fourth year, when the writer took charge of the 

 experiments, found to be mainly dead. The individuals which in the 

 third and later years gave the largest yields are all still living. This 

 indicates that there is probably a crreat difference in the period re- 

 quired by different strains to reac^^ their most productive age, and 



