122 



GRASSES OF IOWA. 



that seedlings of large seeds, owing to their greater vigor, 

 crowd out the seedlings of small seed. A continual selection 

 of the small seeds for several generations, he says, will cause 

 the plants to die out altogether by failing to produce seed, or 

 else a tiny race of beings will, for a time, be maintained. 

 These vegetable runts, the result of insufficient nutrition and 

 insufficient light, are of common occurrence in nature." B. T. 

 Galloway, by growing selected lots of large and small radish 

 seed, found that "the largest seeds germinated more quickly 

 and with more certainty, and produced marketable plants sooner 

 and more uniformly than the small seeds. " The latter, how- 

 ever, "gave porportionally larger plants." In this case, which 

 at first thought seems confusing, we see, as Mr. Galloway 

 suggests, the effect of long continued, natural methodical selec- 

 tion. The radish is cultivated for the root, and selection has 

 been continually directed to increase the size of this part with- 

 out attention to the seeds. If more nutrition is utilized in root 

 development with plants of equal vigor, less would probably 

 remain for seed development, resulting naturally in small seed. 

 Thus, long continued selection, aiming only to increase the size 

 of the root, which is done with some detriment to the seed, 

 might be expected to ultimately lead to an inherited tendency 

 of the small seeds to develop large plants, and vice versa. ' ' 

 The subject of corn from this standpoint, has been quite fully 

 treated by Arthur and Golden.* 



If 



17 

 tL 

 /s 



13 

 /Z 

 // 



3 2 / n / z 3 4 S 6 7 t 'f JO // /z /3 /4 ys /(> 



Fig. 68. Product from large and small seeds. (A.rthur and^GoIden.) 



'Hgil. Sci. 5: 117. 



