New Yokk Agkicultukal Expeeiment Station. 525 



Recent discoveries associated with the name of Mendel, em- 

 phasize the fundamental nature of the great force heredity in 

 determining the characters of living things. " Like begets like," 

 '' Eace is everything," "A chip of the old block," " Like father 

 like son," " Figs cannot be picked from thistles nor grapes from 

 thorn trees," '' The iniquity of the father is visited upon the 

 children to the third and fourth generation," are old and familiar 

 aphorisms recalling the general nature of heredity which present 

 knowledge makes more forceful than ever before. Heredity, in 

 the light of Mendelism, is almost a tight compartment, a closed 

 circle, into which new characters seldom find their way. 



But new characters may get in and in their turn are inherited. 

 HoAv?. The touchstone which Nature uses in introducing new 

 characters into living things has long been known but has been 

 most clearly described by De Vries. It is the phenomenon familiar 

 to all fruitgrowers as a sport which De Vries dignifies with the 

 name mutation. De Vries assumes that new characters in 

 animals and plants are prodnced from existing forms by sndden 

 leaps. The parent remains unchanged during this process and 

 may repeatedly give birth to new fonns. 



Through the work of Mendel and De Vries old theories of 

 breeding have been completely upset, and, in particular, we have 

 changed our views of selection as a means of improving plants, 

 holding that as formerly practiced it is either a worthies^;, a very 

 limited, or at best a very cumbersome method of improving plants. 

 It is now held that most of the differences in plants within the 

 strain of the same variety or species are not transmitted from 

 parent to offspring and that, therefore, selection with them is of 

 no avail. There are, however, two kinds of variations and these 

 must be described. 



Not infrequently wholly new characters, the mutations of De 

 Vries, appear in plants and are transmitted from parent to off- 

 spring. Suppose a branch of russetted, sweet or red apples in a 

 E. I. greening tree ; or a cane bearing white, or red, or seedless 

 grapes on a Concord vine ; or a branch of a Montmorency cherry 

 bearing double flowers, to represent the kind of variations that 

 may come true when propagated from buds or cions. Such varia- 

 tions are relatively rare and many men work among fruit trees 

 a lifetime and do not find them. On the Station grounds where 

 we have under observation eight or ten thousand tree, vine and 

 small fruits, we seek bud-variations, but do not isolate one a 

 year. When such a variation is found, whether or not the new 



