eo. 8 
THE IMPROVEMENT OF THE SUGAR-CANE BY HYBRIDISATION. 319 
result of this work. It is reported that four pedigree hybrids haye been 
raised in Queensland, and in Cuba about six hundred are said to be now 
under investigation. 
The operation of emasculating the flowers has to be performed under 
a dissecting microscope upon a platform 8 or 9 feet above the ground. 
Such an operation, under field conditions, with a strong wind blowing 
is attended with considerable difficulty. Hyen when accomplished, an 
unfavourable season, with very hot, dry winds, or heavy rains, is likely to 
destroy the chance of good results. That so much depends upon the 
season may be seen by the results from Cuba. Four years’ work yielded 
but two hybrid seedlings, while the work of a single favourable season 
produced six hundred. 
Having established the fact that hybrids of sugar-cane can be obtained 
by cross-pollination under control, it remains to discuss briefly the best 
methods of attacking the problem of raising disease-resistaut varieties 
with a large sugar-content. 
7 OUTLINES FOR FururE Work. 
Formerly, with a nearly common standard of perfection, the attempts 
to procure an improved race of sugar-canes centred around breeding from 
the best varieties; but now, by carefully analysing the different charac- 
teristics of the different varieties under cultivation, it may be possible to 
breed methodically for definite objects. 
The work on inheritance carried out by Mendel and communicated to 
the Brinn Society in 1865, and since so ably elucidated by Bateson, 
shows conclusively that the gametes are pure with respect to the 
characters they carry. Further, the work of Biffen with wheat-breeding 
should serve as a model on which breeding of sugar-cane should be carried 
on. By following such methods, instead of making a considerable 
number of crosses indiscriminately with the hope of obtaining some 
improvements, hybridisation on definite lines should now be carried out. 
The first thing to consider, therefore, is what desirable characters are 
required to be chosen. As it is necessary that the hybrids should be an 
improvement commercially, only those characteristics of the cane which 
appeal to the planter should be considered. The chief amongst these 
are : 
(1) Behaviour. under extreme conditions of drought or excessive 
moisture. 
(2) Maturity—whether early or late. 
(3) Disease-resisting power. 
(4) Milling qualities. 
(5) Tonnage of canes per acre. 
(6) Richness of juice in saccharose. 
(7) Purity of juice. 
It would be impossible at the outset to consider all these characters, 
and consequently it would be advisable to work with those which are of 
greatest value economically. 
The essential characters to be considered are resistance to drought, 
resistance to disease, a larger tonnage of cane per acre, richness of juice 
in saccharose, and, in some of the northernmost countries, early maturity. 
