i9o6] DE VRIES— ELEMENTARY SPECIES IN AGRICULTURE. 153 



of minor value the remainder were sown on a field and multiplied 

 without further selection in order to produce all the seed required for 

 the sowing of the whole farm. It took three or four years to reach 

 this quantity. After twenty years of continued selection the choice 

 strain was so much improved as to produce a race distinctly richer 

 than the ordinary varieties of rye in middle Germany, and slowly but 

 gradually it found its way first into the surrounding farms and after- 

 wards over large parts of the country. During this period Rimpau 

 was enabled to sell all his harvest as seed-grain, obtaining in this 

 way a most satisfactory recompense for his labors. Shortly after- 

 wards the rye of Schlanstedt was introduced into France, where it 

 soon overthrew the local varieties, especially in the departments 

 north of Paris. Even there it is ordinarily cultivated from original 

 seed, produced directly by Rimpau or multiplied only during some 

 few generations by seed merchants. 



For our critical purpose, it is highly interesting to note how a 

 French agriculturist. Professor Schribaux of the Institut Agro- 

 nomique of Paris explains the conditions of keeping the Schlandstedt 

 rye up to its original qualities. He says : "In order to do this, care 

 must be taken to sow the seeds on a field which is as far removed 

 as possible from all other cultures of rye. Moreover, the field should 

 be large and protected all around by a hedge of trees and shrubs. 

 Without this precaution the rye of Schlanstedt would soon degen- 

 erate through accidental crosses with the local varieties." Such 

 crosses would, under any other conditions, be unavoidable and soon 

 wholly deteriorate the race ("Almanach du Cultivateur," 1892, 

 p. 69). 



From this judgment, given by an authority who has so much 

 contributed to the wealth of northern France by the introduction of 

 this variety, we may deduce some conclusions as to the constancy of 

 Rimpau's rye. It is clear that Schribaux takes the race to be substan- 

 tially constant, and explains the necessity of continued selection only 

 by the impending danger of crosses with varieties of minor value. 

 Hence it follows that the main significance of the pedigree culture 

 on the farm of Rimpau must be the same, and that at least in later 



