IMPROVEMENT OF THE POTATO. 377 



cheaper methods of production and better varieties make the potato 

 a competitor with the cereals for manufacturing purposes. 



This study deals with such questions as have naturally arisen in 

 trying to form a basis for practical work in potato improvement; 

 and includes an examination of the literature bearing upon the pos- 

 sibilities of attaining this end. The principles underlying practical 

 work in potato improvement are very broad, much too broad to 

 be adequately discussed in a single paper, and yet it seems impos- 

 sible to separate them into narrow lines without ignoring principles 

 which are essential to the work. For this reason it has been thought 

 best to consider briefly such of these as are indispensable, without 

 regard as to whether in every case they have been touched in the 

 experimental work. No attempt has been made to discuss historical, 

 agricultural or economic data, however, except in so far as such 

 subjects relate to the improvement of the potato in desirable hered- 

 itary qualities. A considerable amount of literature has made its 

 appearance since the beginning of the experimental work in 1901 ; 

 but we have endeavored to give a resume of the present status of 

 knowledge of the subjects. 



The writer desires to express his obligation to the Directors of 

 the Illinois and Connecticut Agricultural Experiment Stations, 

 E. Davenport and E. H. Jenkins, through whom was made possible 

 the use of laboratory and other facilities of these stations ; and who 

 have given much helpful advice. Especial acknowledgment is made 

 to Dr. C. G. Hopkins under whose direction the study was under- 

 taken, and who has been a constant source of advice and encour- 

 agement. 



