68 TRANSACTIONS OF THE ILLINOIS 



habit and rendering the plant variable, as the apple, the corn, or the 

 cabbage. So far do the destruction of habit and the promotion of varia- 

 bility go, that even the bud, single in its parentage and usually constant 

 to its nature, finally breaks away from all precedent and becomes radically 

 changed. 



If artificial measures and dealings with plants favor variability, we 

 should then expect to find those plants most variable which exist under 

 circumstances most artificial. Is this the case? All experience in flori- 

 culture and pomology answers, it is. The pelargonium, the petunia, the 

 gladiolus, and the thousands of floral treasures which are and long have 

 been propagated by extension, vary almost infinitely whenever seedlings are 

 raised. The apple, pear, cherry, plum, etc., budded, grafted, for many, 

 many generations, are almost equally apt to vary from parental forms, 

 even though secured from a possibility of crossing. Our garden vegetables 

 which, though regularly reared from seed, are yet, by constant high 

 culture, stimulated away from their old habits, and generally very 

 variable. 



Only some of the cereal grains, and here and there some other indi- 

 vidual plant which has a stronger hold upon habit than common, seem to 

 resist the tendency of culture — propagation by extension and crossing, to 

 produce a wide range of variability. But even they do vary, and vary 

 enough to fill our proposition. There seems to be an essential and char- 

 acteristic difference between the nature of a "sport" variation and a cross 

 variation. That is a sport which is the appearance of hitherto unknown 

 forms or features in a seedling or in a bud and its resulting branch ; is apt 

 to show a vigor and certainty of reproduction, a prepotency not known 

 even in the parent or parents ; it is apt to be — indeed, I think is always — 

 self or single-colored, if the color was one of the changed traits which go 

 to make up the sport; it is apt to be a reversion as well as a sport, chang- 

 ing back to remote parental forms at the same time that it changes to 

 entirely new forms. The cross variation, on the contrary, is lacking in 

 prepotency, variable in its offspring ; it is parti-colored often. If it 

 shows traits of reversion, it seldom, if ever, shows new traits at the same 

 time. 



The very fact that sports and cross variations originate differently 

 suggests the cause of their difference in character, the disturbing cause in 

 each respective case working in some special direction. 



The sport arose in answer to one kind of a call made upon the par- 

 ents ; the cross also arose in answer to a call made upon the parents, but 

 a different kind of call made in a different manner. 



When, from any cause, or under any circumstances, a variation has 

 occurred, be that variation ever so slight, if it is an improvement, we 

 may set to work to intensify and fix it by selection and breeding, and 

 thus, in time, a new habit may be developed. 



If we were to inquire critically as to what elements the civilization 

 and enlightenment and scientific progress we so love to boast consist in, 

 we must conclude that it is simply an increasing sovereignty over the 

 forces of nature — an increasing knowledge of the hitherto hidden ways of 



