284 PLANT-BREEDING 



out Sweden. Similar results have been obtained with the 

 white and the crimson clover. 



Many other species of leguminous plants are available 

 for the culture of green fodder. Different kinds of lucerne, 

 of which the alfalfa is the best known species, some forms 

 of Lathyrus, and others have been included in the tests. 

 They are rich in elementary types, but even of the botanical 

 species the agricultural significance was hardly known. 

 Some instances may here be given. Lathyrus heterophyllus 

 is an early ripening species, with sweet tissues and a vig- 

 orous growth. It is an excellent yielder. Lathyrus praten- 

 sis and Vicia Cracca, two common species along road sides 

 in Europe, recommend themselves by their fitness for mixed 

 cultures on meadows. A richer type of Lotus uliginosus 

 with broader leaves and a resistant variety of Lathyrus 

 sylvestris have been isolated. 



Potatoes, beets, and even the ordinary meadow-grasses 

 have been subjected at Svalof to the same methodical study. 

 It would take too long to give all the details. It may suffice 

 to choose the grasses as a last instance. On meadows, the 

 vegetation is a more or less mixed and motley array of nu- 

 merous types, belonging partly to the grasses and the legu- 

 minous family, partly to other less valuable or even obnoxious 

 species. The value of the different kinds of grasses depends 

 mainly upon the question whether they are at their fullest 

 development at the time when the hay is cut. Some species 

 are too early, become woody, and lose their nutrient qualities 

 before the harvest. Others are too late, and have only pro- 

 duced part of their foliage at that time. Both, of course, 

 constitute a distinct loss, and it must be considered a chief 

 aim in the improvement of meadows to replace them by 

 types which will ripen simultaneously. 



Now the experiments at Svalof, although as yet only 

 few in number, have shown that the ordinary grasses are 



