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crease in productiveness due to crossing has been marked in 

 many instances. Marked increase in productiveness has 

 been obtained from tomato crosses, even when no other re- 

 sults of crossing could be seen." 



Darwin's experiments made with tobacco gave equally 

 positive results. The crossed and self -fertilized plants were 

 treated in different ways: Firstly, under very close competi- 

 tion; secondly, greatly crowded in large pots; thirdly, sown 

 in poor and good ground so as not to be crowded. In each 

 case the crossed plants were superior in every way. The 

 crossed seed germinated easier, more rapid growth of the 

 seedlings while yonng, and earlier flowering of mature 

 plants. Ultimately they exceed in height also. The 

 superiority of the crossed plants was plainly shown when 

 they were weighed, — cross to self-fertilized was as 100-37. 

 Hildebrand had similar results with a species of Oorydalis- 

 lie cross-fertilized sixty-three flowers. Of these sixty-eight 

 set fruit with 4. 5 seeds per plant. He then self fertilized 

 sixteen flowers of these; only three set fruit. He then self- 

 fertilized twenty- seven flowers; none set fruit. 



Behrens cites the following case: "Two tulips in separate 

 pots were brought into the house shortly before the flowers 

 opened. Gauze bags were tied over each of the flowers. 

 When full grown the gauze was removed. One was self- 

 fertilized and the other cross-fertilized. Both were again 

 covered with gauze and left undisturbed. The result was 

 that the cross-fertilized developed perfect fruit containing 

 seeds capable of germinating. The close fertilized produced 

 a stunted capsule with seeds incapable of germination." 



Change of Seed. It may be well to refer here to the 

 well-known belief that change of seed is advantageous. 

 There can be no question that small changes will be benefi- 



