FOURTH NATIONAL FLOWER SHOW 173 
of plant-breeding were based largely on a study of individual plants. It has 
been within recent years that interest has arisen in unit characters in individual 
plants and animals; but with the realization that these characters do occur in 
all individuals to a greater or less degree, and that they are transmitted to off- 
spring in a rather definite ratio, there has arisen a clearer conception of methods 
for reproducing desirable characters in the offspring. 
It has been stated that in breeding roses there is much complexity. There 
are many unit characters which must be transmitted to the offspring, and 
therefore simplicity of action is impossible. Among these unit characters are 
color, fragrance, size of flower, substance of petals, strength of stem, resistance 
to disease, character of foliage, and hardiness. To combine all these desirable 
qualities in one individual, requires most careful selection of parents and 
painstaking breeding which must necessarily extend over a considerable period 
of years. The color factor alone is exceedingly complex, as is shown in a most 
carefully prepared paper on "Heredity of Color in Phlox Drummondii," by Dr. 
A. W. Gilbert, Department of Plant Breeding, at Cornell University and pub- 
lished in the "Journal of Agricultural Research," July 15, 1915. The general 
principles which govern heredity of color in phlox govern color in roses, although 
their application is much more complex in the latter case. 
The rose is, therefore, not an easy plant to breed and get marked improved 
results. The period of "watching and waiting " is a long one. In other words, 
it is a plant of "frequent generations" as are many other species of ornamental 
plants. After the parents have been crossed, it takes a long time for the seed 
pods to mature, and after the seeds have ripened they are difficult to germinate. 
It requires the most careful treatment to get even a fair percentage of germina- 
tion. The blooming period of the offspring does not follow quickly, and the 
hybridist has to wait a long period for results. Even when the work has been 
carried out along modern scientific lines and careful attention has been paid to 
all principles of genetics, the results are often discouraging. 
However, our American men of science are awakening to the possibilities 
which lie in the rose family, and the future of this plant is promising. Plant- 
breeders have found corn and wheat wonderfully plastic under scientific de- 
velopment, and the belief is strong that the rose may, in the near future, be de- 
veloped into tyi^es far superior to those of today. 
The Lectures 
By Men Who Know Will be Interesting 
Don't Fail to Hear Them 
