'220 Improvement in Indian Stn/arcanes 



constant in different localities and under diverse conditions? What 

 stability is to be expected in such minute vegetative separating marks 

 and what are the limits of variabihty, especially in quantitative char- 

 acters ? There is no doubt that the sugarcane responds very readily 

 to change of habitat. This fact will increase the scope of the detailed 

 study described in the last section, in that the same varieties must be 

 studied for several successive seasons both in North India and at 

 Coimbatore. We already know of characters which are unstable in 

 certain varieties under changed conditions, although they appear to 

 vary less in others. The ivory markings in the joint are usually a good 

 character, but in some kinds of cane they are readily affected by changes 

 in climate (moisture?). The colour of the cane has been observed to 

 change in some varieties in transfer. Canes which appear to be im- 

 mune to fungus attacks in one district are at once attacked and des- 

 troyed by the same species of fungus in another. There are a number of 

 other characters which have been noted as varying in this way, and it 

 is possible that, while firmly fixed in certain kinds of cane, they are 

 variable in others. These facts will naturally increase our difficulties 

 when we attempt to trace the characters of any parent in a seedling by 

 observing its morphological characters. But, in consideration of the 

 facts noted in the next paragraph, it will be seen that these difficulties 

 are greatly increased. 



Problem 7. Of what value are the characters noted above in 

 separating seedling canes ? Are any of the minute differences observed 

 in varieties propagated vegetatively handed down unaltered in seedlings 

 derived from them? At present there is not sufficient material avail- 

 able to answer these questions. But one of the most obvious features 

 in any batch of seedling canes from a common parentage is the extra- 

 ordinary amount of variation among them. And this is especially 

 noticeable in those characters of habit which appear to be so stable 

 and valuable in varieties in the field. The seedlings appear to differ in 

 every direction — habit, joint, colour, leaf, juice, etc. We have already 

 collected a certain amount of material for the detailed study of this 

 question. Last year we obtained 70-80 seedlings from Strakarchynia 

 (a thin Behar cane) fertilised by Saccharum spontaneum; 13 from 

 Chin (a thin U.P. cane) also fertilised by Saccluirum spontaneum, and 

 71 selfed seedlings of Saretha (a thicker cane of the U.P.). As far as 

 time has permitted, a detailed study has been made of these seedlings 

 and the descriptions of them recorded, and it is hoped that, when 

 these descriptions are analysed, some useful facts may be obtained. 

 One difficulty is encountered, however, in our inability to apply the 



