15 



ing the purity of races yielding the standard classes of the present 

 day. Such selection forms the basis of any scheme which aims at 

 eliminating " degeneration," which, in its ultimate form, is interpreted 

 as due to an inherent plant character giving to the type a limited 

 span of life. 



Secondly, it must be directed to the discovery and subsequent 

 isolation of new and hitherto unrecognized types', whether the novelty 

 affects the quality of the cotton or the behaviour of the plant in the 

 field. It will cover the search for such plants as develop improved lint, 

 a higher ginning percentage, a vigorous habit accompanied by high 

 yield or an early maturation. 



2. Hybridization. The aim of such work is, ultimately, identical 

 with that of the latter form of selection. Here, however, the method 

 is directed. But more than this is involved. We are still ignorant 

 of the factors controlling many of even the more obvious plant 

 characters, and there is much preliminary work to be done in this 

 direction. 



3. Physiology. Physiological investigation will bear on the 

 general problem at several points. At each stage of its history the 

 plant is in direct response to its environment, and growth will be 

 controlled by one or other of the factors composing that environment. 

 In its broadest outline physiological investigation will be directed 

 to determining the limiting factors throughout. In the more particular 

 aspect it will be directed to determining the effect of root interference, 

 the causes of bud and fruit shedding, and the effect of such factors 

 as water supply on quality of lint. 



(3) AGRICULTURAL. 



In the direct sequence, which we have termed primary, agri- 

 cultural investigation will carry on the tests of the pure races a stage 

 further, and will require facilities for working up a seed supply of such 

 as successfully pass these tests. Such tests must include not merely 

 comparative trials in one area for, as we have seen, not the least 

 important aim will be the demarcation of type tracts but in several 

 areas. Trial grounds will thus be required in each well-defined tract. 

 The working up of a seed supply, involving, as it does, a different 

 set of conditions, and one which will effectively maintain purity, 

 requ ; res separate treatment 



Secondly, provision must be made for subsidiary lines of agri- 

 cultural investigation, cultural and manurial experiments, and 

 experiments on the water requirements of the field crop. Such 

 investigations are linked, on the one hand, with the physiological 

 work already referred to, and, on the other, with the general agri- 

 cultural problems of the country. 



