48 
The Proposed Solution.—We believe the problem can be solved, 
first of all, by combining the quality of disease resistance inherent 
in the oriental species, with the tall-timber character, i.e. the lofty 
height growth, of the American species. Such a combination may 
ection 
pee 
be brought about by continued breeding, accompanied by se 
of desirable types. In the meantime, also by breeding, desirable 
characters of other species may be incorporated into the new stock, 
It is on account of this last consideration that we are trying to 
develop many new hybrids, in addition to the chief combinations 
of Japanese-American and Chinese-American. For, leaving aside, 
for the moment, the qualities of height growth and disease re- 
sistance, many of the species, or even races within species, have 
other desirable qualities, such as cold or drought resistance, resis- 
tance to insect attack, and robust growth, 1e., unusual growth im 
thickness, as distinct from rapidity of growth in length. The qual- 
ity of the nuts, too—their flavor, size, and abundance, and the pre- 
cocity of blooming and fruiting, are some of the points that should 
be considered. For, although our primary aim is to restore a tim- 
ber tree, the nuts have some value, even though proportionately 
small. Finally, it should be borne in mind continually that valu- 
able recessive (1.e. hidden) characters may exist in many of the 
species, which continued breeding may bring to light. 
For the beneht of those unfanular with plant breeding may we 
say that when, for example, plants of two different species are to 
— 
be bred together or crossed, the process consists essentially of 
pollinating the pistils (containing the eggs) of the plant of one 
species with the pollen (producing the sperms) from a plant of 
the other species. Such pollination, if successful, results in a 
seed containing a “ half-breed ” embryo, t.e., a young plant which 
are 
contains within itself a combination of the characters of both 
parents. 
Propagation.—lf and when we succeed in developing a disease 
resistant tree of timber type, there would always remain. the 
difficulty of reproducing it by its nuts; for, as every botanist 
knows, these could not be depended upon to produce trees like 
the parent. Vegetative propagation is therefore the only solution ; 
ie., the growing of new individuals from parts or pieces of the 
individual which it is desired to multiply. We have tried re- 
