810 Fluctuations 



preciation of all the qualities of the selected 

 plants is the common feature. Morphological 

 characters, and the capacity of yielding the 

 desired products, are the first points that 

 strike the breeder. The relation to climate and 

 the dependence on manure soon follow, but the 

 physiological and chemical sides of the problem 

 are usually slow of recognition in the methods 

 of selection. When visiting Mr. de Vilmorin at 

 Paris some years ago, I inspected his laboratory 

 for the selection of potatoes. In the method in 

 use, the tubers were rubbed to pulp and the 

 starch was extracted and measured. A starch- 

 percentage figure was determined for each 

 plant, and the selection of the tubers for plant- 

 ing was founded upon this result. In the same 

 way wheat has been selected by Dippe at 

 Quedlinburg, first by a determination of its 

 nitrogenous contents in general, and secondly 

 by the amount of the substances which deter- 

 mine its value for baking purposes. 



The celebrated rye of Schlanstedt was pro- 

 duced by the late Mr. Rimpau in a similar man- 

 ner and was put on the market between 1880 and 

 1890 and was received with great favor through- 

 out central Europe, especially in Germany and 

 in France. It is a tall variety, with vigorous 

 stems and very long heads, the kernels of 

 which are nearly double the size of those of the 



