440 FARMERS' INSTITUTES. 



ferent would tend to great variability. The fixed characters of the parents 

 would be very unstable in the offspring, and all attempts to breed toward a 

 fixed type would be interfered with by the tendency to reversion. 



Hence, varieties for crossing should differ only in minor characters. Then 

 we may expect stability of character in the progeny, and that additional 

 vigor and productiveness which is the aim of crossing. 



CHANGING SEED. 



Experiments have shown that the crossing of plants of the same variety 

 which have been grown under different conditions, will yield as good if not 

 better results than crosses between distinct varieties. Mr. Darwin, in his 

 admirable work, " Cross and Self-fertilization in the Vegetable Kingdom," 

 remarks on this point: "That the advantages of cross-fertilization do not 

 follow from some mysterious virtue in the mere union of two distinct indi- 

 viduals, but from such individuals having been subjected during previous 

 generations to different conditions, or to their having varied in a manner 

 commonly called spontaneous, so that in either case their sexual elements 

 have been in some degree differentiated." 



It is a very common practice with gardeners to obtain, at intervals, an 

 entirely new stock of the seed of certain plants from a distance. Their 

 crops of these plants when grown from the same stock, under the same con- 

 ditions, constantly diminish in spite of careful attention to seed selection 

 and cultivation. It is said that the onion growers of Connecticut, who 

 import their seeds from Tripoli, are obliged to renew their stock every three 

 or four years. The deterioration in this case follows undoubtedly from 

 conditions of soil and climate. 



Farmers often resort to this same plan of changing their seed corn and 

 seed wheat. Mr. Darwin suggests as a better plan, to obtain some seed of 

 the same variety which has been grown under different conditions, and plant 

 it with your own. " The two stocks would then intercross with a thorough 

 blending of their whole organizations, and with no loss of purity to the 

 variety, and this would yield far more favorable results than a mere exchange 

 of seeds." His careful experiments abundantly prove that wonderful results 

 are to be obtained from crosses of this kind. 



Dr. Beal, at the College, obtained two kinds of corn, nearly or quite alike, 

 irom two localities, crossed them and planted the crossed seed in a field of 

 dent corn. The yield from the crossed seed excelled that from the corn not 

 crossed as 153 exceeds 100. On farms where the soil is various in character, 

 an effect equivalent to change of seed or change of condition is brought 

 about by growing the crop each year on a different soil. 



CLOSE BREEDING. 



In connection with the question of changing seed arises the question of 

 close breeding. How long will a variety maintain its vigor if grown year 

 after year from the same stock, with no admixture of new blood? Crossing 

 between neighboring plants continually occurs in fields of corn, and to some 

 extent in fields of wheat. It is more general in corn than in wheat because 

 the flowers of wheat are constructed to aid self-fertilization. But many 



