98 TILLERING IN INDIAN SUGARCANES 



assumed the characters of one of a lower order which had died, and particu- 

 larly the difl&culty of obtaining representative clumps and plants in certain 

 varieties ; the relative incidence of different diseases, such as mealy bug in the 

 young shoots, the deformations caused by moth-borer and white-ants and the 

 extraordinary manner in which some varieties appeared to be inmmne to any 

 infection of red rot ; the effect of all these factors on the varietal characters, 

 and the frequent geographical grouping of subdivisions brought out by them. 



It is thus not surprising that, dviring the course of the work, the general 

 scope of the observations has from time to time undergone some modification, 

 and it was not until the second year that a full scheme was developed for the 

 study of each stool dissected. In some of the tables of measurements, only 

 the dissections during 1917-18 are therefore considered. It was obvious that 

 it was necessary to drop most of the side issues, after recording a note, as soon 

 as a decision had been arrived at, and the f ollowmg were the main lines followed 

 in the second year, in which by far the larger number of dissections were made: — 

 the evolution of a scheme of branching for each plant, variety or group and the 

 discovery of a suitable formula and set of conventions for expressing this ; the 

 relative thickness of each cane at two feet from its base, the length of the basal 

 thickening, short-jointed portion, and the immber and length of the joints 

 in the first two feet after this basal portion had been passed ; the rate of matur- 

 ing of the young plant as regards cane-formation ; the presence of curva- 

 tures at the base, runners, deaths, injuries and abnormalities of all kinds, etc. 

 Details on these points are recorded in every dissection, and the various sum- 

 maries and conclusions contained in this part of the Memoir have been derived 

 from them. 



