SCIENCE AND COTTON 303 



direct relation to the production of good cotton. Insects and 

 fungi may be classified as controllable or uncontrollable, accord- 

 ing to their kind, and to the circumstances. 



The factors of the environment which are uncontrollable are 

 climatic. Some mitigation of their effects may be attained by 

 methods of cultivation, or by choice of pure strains which suit 

 the climate. When this has been done there remains a residuum 

 of climatic effects which may modify the crop from year to year 

 profoundly, but are beyond human control. The utility of 

 crop-records and forecasting becomes apparent in this connec- 

 tion, since to be forewarned is nearly as good as to prevent. 

 Once the physiological work has progressed sufficiently far to 

 be used in the forecasting system, much of the objection to 

 erratic climate will disappear, since the trade can be warned 

 in advance by one to four months before the cotton reaches the 

 quays of the port of export. 



The connection between knowledge of the operation of 

 environmental factors, and the production of uniform cotton 

 may perhaps require some explanation, before passing on to 

 consider such research as could be effected away from the 

 cotton-fields. 



Cotton is in many respects a somewhat exceptional plant, or 

 at least it appears to be so at present. It is most successful 

 commercially in circumstances where it is rendered almost inert 

 during every afternoon of the season. Under these severe 

 climatic conditions some forms of " self-poisoning " are very 

 easily induced in its cells. We shall recur to these auto-toxic 

 phenomena shortly, but meanwhile it may be noted that such 

 actions as delayed irrigation may lead to enfeebled growth in 

 all parts of the plant for some time afterwards, the length and 

 thickness of the lint being affected incidentally, and spoiling the 

 regularity of the cotton picked. So frequent are these pheno- 

 mena that the writer has ventured to define the aim of a cotton 

 cultivator as " a fight against self-poisoning." The plant has to 

 be worked as nearly to the danger-points as is possible without 

 transgressing them, if good results are required. 



An accurate knowledge of what is dangerous, and what is 

 not, will certainly be of use in guarding against these internal 

 troubles. Moreover, it is not improbable that the whole specifi- 

 city of such a character as the length of the fibre may be cognate 

 with them, and that further study may enable us to produce 



