IV. NOTE ON A METHOD OF BUILDING UP. AN IDEAL CANE BY 

 AVERAGING MEASUREMENTS AT SUCCESSIVE JOINTS. 



Averaging the len.gth of the organs at succep^ive joii'.ts of the care preseiitji 

 many difficulticfi, the chief of which if; that the caney are of different lengths 

 and do not contain, the same number of join.ts. Some of these difficulties 

 have been alluded to in. a previou;^ Memoir* where it wau decided that, while 

 six canes were in.sufficient for rehable averages to be obtained, measurements 

 of twenty would at an.y rate demon.strate the presence of early an.d late classes 

 of canes in the crop. The latter number has been, adopted in all subsequen.t 

 measurements, an.d a considerable amount of time has been devoted, to the 

 elucidation of the problem. This number is considered sufficien.t to rule out the 

 occasional abn.ormal variations an.d. if the selection of cane;' is carefullv checked. 

 wilL it is held, give fair averages from which the mode of growth caii. be ascer- 

 tained. It is recognized that soil, manuring, rainfall and temperature, will 

 have con.siderable influence, but if these are equal for all varieties, the intriii.sic 

 diflferences in. growth will make themselves apparent in comparison.s. It has 

 trai\spired that en.viron.ment has a considerable effect upon growth in len.gth 

 of the organs at different parts of the can.e, an.d characteristic curves have 

 been, obtained in a series of canes grown at Taliparamba, on. the west coast, 

 and Samalkota, on the east coast, of the Madras Presidency. It is possible, 

 from a glance at the curve of growth, to say at once in. which of these two 

 localities an.y variety has been planted. This fact makes it all the more 

 necessary, in comparisons, to study all the canes at the same place and un.der 

 the same coiKiitioiis. We cai\n.ot safely compare the growth curve of one 

 cane growi\ in. North In.dia with that of another grown, at Coimbatore. 



The twenty canes are chosen at haphazard, but the collector will obviously 

 pass over such as are meagre and stunted, and the average will, therefore be 

 somewhat higher than, in the whole crop. The object aimed at is to obtain 

 twenty average canes which have become fully developed. When on.e con- 

 biders that these twenty canes will vary greatly in general height, in the luimber 

 of the joints and in other respects to be referred to below, it would seem w ell -ni'di 



* -Mcin I. p. 35. 



