176 STUDIES IN INDIAN sItGARCANES 



in the two groups of canes should be borne in mind, because they are more or 

 less repeated in the length curves of the leaf-sheath and lamina, and emphasize 

 the fact that the organs in varieties of the Saretha series are longer than those 

 in the Sunnabile group, and that the maximum development takes place earlier 

 in the former group in all cases. The Saretha cane develops more rapidly in 

 all its parts. 



We have now at our disposal the data on which to build the ideal cane for 

 each group, in that we kn.ow the relative length of joint in each, as well as the 

 variations in thickness at different points, and to complete the picture a 

 reference may be made to a preceding paragraph where the thickness of the 

 canes in different regions is discussed. In preparing such a scheme for an 

 ideal cane, it must of course be borne in mind that these particular curves 

 refer only to canes of the two groups grown in the Cane-breeding Station. 

 The growth of canes of any one variety varies considerably with chmate and 

 soil, as has been abundantly demonstrated by measurements taken at various 

 places in North and South India. But the main differences between the two 

 groups, shown by the measurements and curves, appear to hold good wherever 

 the canes are grown under identical conditions. 



Colour of Cane. 



Observations on the colour of canes are extremely difficult, and the result>: 

 are often confusing. This is not only due to the fact that the colour of a 

 joint varies constantly with its age, but also that it is affected by the presence 

 or absence of bloom (which is often p?rtially rubbed off), and the blushing of 

 parts which have become accidentally uncovered by the leaf- sheaths and 

 exposed to the sun and weather. Furthermore, the colour of some canes is 

 known to change considerably after being cut, while it does not in others, 

 and the same apphes to canes taken from one locahty to another, where some 

 assume a totally different tone in the new conditions. The present summary 

 is based upon a series of observations at different stages of growth in the canes 

 harvested in 1916 and 1917 in the Cane-breeding Station, checked to a large 

 extent by notes on their colour in the localities from which they have been 

 collected. The views of different observers have been collated, and these 

 latter included general, bulk observations made in the field and detailed 

 analyses, joint by joint, in the laboratory. 



One of the first results of this study has been the discovery of a distinct 

 cleavage, in the Saretha group, into those which develop brown markings on 

 the stem and those that do not. The former include most of the thin, primitive 



