126 

 cial, but they may be also fraught with danger. The question 

 of climate must always be taken into consideration. Bailey ^ 

 who has given this question much attentions, says: ''Even a 

 slight change, as between farms or neighboring villages, 

 sometimes produces marked results, such as more vigorous 

 plants and often more fruitful ones. We must not suppose, 

 however, that because a small change gives a good result, a 

 violent or very pronounced change, gives a better one. 

 There are many facts on record to show that great changes 

 often profoundly influence plants, and when such influence 

 results in lessened vigor or lessened productiveness we call it 

 an injurious one Now, this injurious influence may result 

 even when all the conditions in the new place are favorable 

 to the health and development of the plant; it is an influence 

 which is wholly independent, so far as we can see, of any 

 condition which interferes injuriously with the simple pro- 

 cesses of growth. Seeds of native physaHs or husk-tomato, 

 were sent to me from Paraguay in 1889 by Thf)mas Morong, 

 then traveling in that country. I grew it both in the house 

 and out of doors, and for two generations was unable to 

 make it set fruit, even though the flowers were hand- 

 polliuated; yet the plants were healthy and grew vigorously. 

 The third generation grown out of doors set fruit freely." 



The husk-tomato experiment certainly shows that it is 

 not advantageous to have very great changes. The plant 

 must become accustomed to its new conditions before it will 

 succeed. 



Bolley, ^* speaking of wheat seed, says: "Those who 

 grew the samples associated with like varieties of home-grown 

 seed have quite unanimously reported that there was no 

 marked difference in growth and development." 



8 Plant breeding. 



8a North Dakota Agricultural Experimental Station, Bull. No. 17, p 86. 



