III. NOTE ON THE DISSECTION OF STOOLS. AS DEMONSTRATING 

 THE SYSTEMS OF BRANCHING AND THE THICKNESS OF 

 EARLY AND LATE CANES. 



The i)reseiiice of early ajid late oan.es in the same clump has been referred 

 to in the two previous Memoirs,* ajui a further note may here be added. In 

 the first Memoir it was noted that, in the 20 canes in which measurements of 

 joint length were made at the Gurdaspur Farm (in 1913-14), there were in 

 certain varieties two classes of canes, differing sufficiently widely to throw 

 the curves of length into some disorder. After more study it was found that 

 these two classes were formed at different periods of growth in. the clumj). The 

 morphological characters of these two kinds of canes were summarized a,s far 

 as possible. The first formed canes were seen to have more joints, to com- 

 mence with shorter ones and to be on the whole thicker than those formed 

 towards harvest time. It was inferred that there might be important differ- 

 ences in the richness of the juice, but no analyses were available. In the second 

 Memoir chemical analyses were given of early and late canes, and it was seen 

 that the former have uniformly richer juice. At the same time it was shown 

 that, while certain varieties habitually develop these two kinds of canes, it is not 

 so in others, and the presence or absence of early and late canes in a clump 

 becomes a varietal or even group character of some importance. These results 

 have been confirmed by further observations, except in one respect. It 

 was noted m Gurdaspur that the late formed canes were thinner than those 

 formed earlier in the year, and it was contended that the former had therefore 

 nothing to do with the thick watery, mostly immature, canes which are seen 

 in many clumps at crop time. In the varieties grown at Coimbatore the 

 dissection of stools has shown that, as regards thickness, the position is reversed. 

 The first formed canes have, it is true, more joints and these are on the average 

 shorter than in the later ones, but there is a regular series of increases in thick- 

 ness from the first formed cane to those of its successive branchings. The main 

 cane is the thinnest, branches of the first order are thicker, those of the second 

 thicker still, and so on. The undoubted fact that this does not apply to the 

 early and late caries measured at Gurdaspur is thus anomalous, but it seems 

 possible that the latter, being developed late in the season, at a time when 

 growing conditions were unfavourable, may reflect this fact in their relative 

 thinness. Further observations are however not at present possible there. 



*Mem. 1, p. 38 and Mem. 2. p. 158. 



