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BOTANY: A. B. STOUT 
plus races respectively by long continued selection in opposite directions. 
Those differences accordingly were based on residual heredity, not on changes 
in the hooded gene proper. For when the residual heredity was equalized, 
the hooded character appeared substantially the same in the two races. These 
findings harmonize with the idea that the residual heredity in question con- 
sists of several modifying genes independent of the hooded gene proper. An- 
other point favoring that interpretation is the increased variability of the 
hooded character following the first cross, and its subsequent decrease fol- 
lowing the second and third crosses. See the column, standard deviation, 
in tables 1 and 2. 
These results favor the widely accepted view that the single gene is not sub- 
ject to fluctuating variability, but is stable hke a chemical compound of def- 
inite composition and changes only similarly, by definite steps (mutation in 
the sense of Morgan, not of DeVries). They offer no obstacles to the prop- 
osition of Johannsen (ably supported by East), that a gene terminology is 
adequate to express all known varieties of inheritance phenomena. 
The full results of this investigation will be pubhshed by the Carnegie 
Institution of Washington. 
^ Bateson, W., Report I to the Evolution Committee of the Royal Society, 1902, p. 12. 
2 Castle, W. E., and Phillips, J. G., Carnegie Inst. Washington, Pub., No. 195, 1914. 
3 Johannsen, W., Elemente der exakten Erblichkeitslehre, 1909. 
* Castle, W. E., and Wright, S., Carnegie Inst. Washington, Pub. No. 241, 1916. 
BUD VARIATION 
By x\. B. Stout 
New York Botanical Garden, New York City 
Communicated by R. A. Harper, February 26, 1919 
The common experience of horticulturists and plant breeders is that prop- 
agation by buds, cuttings, layering, etc. (asexual propagation) yields a com- 
paratively uniform progeny, while propagation by seed (sexual reproduction) 
and especially that which involves mating of unlike parents whether of the 
same or of different species or races, is likely to give decided variation among 
progeny. On the other hand, common experience and practice recognizes the 
widespread occurrence of bud variations and the importance of utilizing them 
in developing new types of important commercial races, or in maintaining 
old races at a high standard, as is well illustrated by the recent studies 
(Shamel and others 1918) of bud variations in the citrus fruits. 
In scientific and theoretical breeding, much attention has been given to the 
study of heredity in sexual reproduction. In many species this is the only 
method that can be utilized, and a knowledge of such heredity is of great prac- 
tical as well as of theoretical interest. When, however, the question arises re- 
