334 REPORT OF THE CONFERENCE ON GENETICS. 
whereas many of the seedlings at present are immune to one disease, they 
are more or less susceptible to another—and also that a large number of 
varieties be at the disposal of cane-planters, owing to the great differences 
in climate and soils of cane-producing areas. 
That climate and soil are the paramount influences exerted in the 
sugar-producing capacity of different varieties has clearly been shown by 
the difference in yields and other characteristics manifested by the same 
cane in different localities. 
Therefore, following the example of European beet-growers, who think 
that the practice of persistently growing their crops under the same 
conditions of soil and climate is a mistake, the seedling canes are dis- 
tributed in experimental plots on widely different areas and under 
different conditions. The seedlings are also grown in competition for a 
number of seasons before any definite conclusions are drawn as to their 
relative value, owing to the varying time of their maturity, the 
rapid deterioration of over-ripe canes, and the varying germinative power 
of the seed cuttings. 
Whereas considerable improvement has been made by selection and 
natural hybridisation, it is expected that hybridisation under control 
should give desired results more rapidly, for by the careful choice of 
parents it is hoped to combine some of the good qualities of both parents 
in the offspring. 
The chief difficulty against obtaining large numbers of hybrids has 
been due to the small size of the flowers and the general habit of growth, 
but by careful manipulation, as described in the “ West Indian Bulletin,” 
vol. v. pp. 362-3, and vol. vi. pp. 3894-402, these difficulties can be 
surmounted, and good results should follow in seasons favourable to 
hybridisation experiments. 
The increasing fertility of the newer seedlings—as shown by the fact 
that recently nearly 1,000 seeds from a single inflorescence have been 
known to germinate, whereas a few years ago thirty to fifty was the 
greatest number recorded—makes it probable that many of the difficulties — 
that have previously kept this work in check will sooner or later be 
overcome. 
Probably the greatest improvement in the future will result from first 
analysing the different characteristics of the varieties to be used as parent 
canes, by raising large numbers of self-fertilised seedlings and then 
building up an ideal cane, which will stand the rigorous tests of field 
selections and analyses in the laboratory. In the carrying out of this 
work great variations will be noticed, owing to the hybrid origin of the 
varieties to be used for crossing purposes; but then, by raising large 
numbers of self-fertilised seedlings, the heredity value of the parent 
varieties may be learnt from careful analysis of the offspring. In other 
words, an examination of varieties of canes for the so-called “ centgener 
power’ of Hays may be of practical importance. 
In short, “the great expectations once held of seedling canes may not 
have been realised,’ yet “the greatest hope for the future lies in the 
expectation that it may become increasingly practicable to raise canes of 
definitely known parentage from carefully selected plants possessing to the 
greatest degree the characteristics of disease-resistance, high sucrose yield,. 
