EXPERIMENT STATION REPORT. 449 



Notes npon " Magnns-Ponderoaa " Crosies. 



A block of thirty plants of the cross of ''Magnus" (io) upon "Pon- 

 derosa" (103) were grown. This was the second generation of the 

 mingling of these two varieties, both strong in their peculiarities. The 

 "Magnus" is a standard, coarse-leaved ("potato leaf") sort, with re- 

 markable vigor, producing a tall plant and fruit of medium size and 

 quite uniformly deep apple-shaped. The wall is thick and the seed 

 cavities are from five to eight, with usually a central core unbroken 

 with seed cells. The "Ponderosa," one of the very popular tomatoes, is 

 a very vigorous plant of the fine-leaved type and produces fruits often 

 of unusual size, but sometimes objectionable because of their flatness 

 and irregularity of outline. The center is much broken up by the 

 many seed cavities, in which the seeds are comparatively few in num- 

 ber. The two varieties, it is seen, differ in character of foliage and 

 form and internal structure of the fruit. They both agree in the color, 

 which is the so-called "pink" or "purple." 



During last winter plants of both these sorts and the cross between 

 them were grown in the greenliouse, and even under the unfavorable 

 conditions of lack of abundant sunlight, due to high neighboring 

 buildings, they showed that vigor and fruitfulness were their strong 

 qualities. 



In the field the plants were of the second generation and showed 

 the two types of foliage, there being twenty-one of the fine-leaved 

 and nine of the coarse-leaved kind. This accords somewhat closely 

 with what might be expected under Mendel's law where the fine- 

 leaved type is assumed as dominant and the coarse-leaved the recessive 

 character. 



The fruits have all been of the "pink" color, and therefore true to 

 both parents, as might be expected. There has been quite a range in 

 size and shape among the various plants. Greater uniformity pre- 

 vailed in the coarse-leaved plants, and this is as if the "Magnus" blood 

 was dominant, but the fruits were not the same as those of "Magnus" 

 grown elsewhere for comparison. The fruits of the "Magnus" type 

 were larger and the seed cavities were more numerous tliaii the true 

 "Magnus." 



In other words, the size and shape of the fruit are altered in the 

 recessive plants of this cross. 



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