C. A. BARBER 193 



Suunabile group ; averages of 15 varieties : 



11-4, 11-9, 12-3, 124, 12-4, 12-4, 12-3, 12-2, 12-1, 12-1, 12-1, 12-1, 11-9, 

 11-8, 11-7, 11-5, 11-7, 11-6, ll-(3, 11-5, 11-3, 11-3, IM, 10-8, 9-7, 6-2, 2*1, 0-6, 

 0-2, 0-J. 



Upon comparing the curves plotted from these figures, the first matter 

 for notice is their extreme shortness, the Sunnabile excess number being 

 reduced to one sheath, as was the case in the joints. The Sunnabile curve is, 

 it is true, lower, flatter, longer, as was the case with the 1916 curves, it reaches 

 a lower maximum than the Saretha and crosses it about half way along its 

 course ; but there is far more resemblaiice between the curves of the two 

 groups in 1917. In one particular is this especially noticeable. The three 

 lowest sheaths are actually longer in the Sunnabile group, instead of being 

 much shorter, and the initial rise in length is much steeper than was to be 

 expected. This may be due to the conditions of growth, which may have 

 affected the varieties of the two groups differently, but it is only fair to state 

 that these initial sheaths were often absent or not susceptible of measurement, 

 and the averages for the first few are accordingly much less reliable. Never- 

 theless the 1917 curve for the Sunnabile varieties is rather steeper than usual 

 in this group and approximates in this respect to that of the Saretha group. 

 Considering all things, more reliance is to be placed on the curves obtained 

 ii\ 191(5, and the general differences noted in it hold, in a diminished degree, 

 with those obtained ui the immature canes of 1917. In the circumstances 

 detailed above, I should feel hiclined to build up the ideal cane rather from the 

 1916 curve, with the proviso that the differences between the length of leaf 

 sheath in different parts of the canes in the two groups may be somewhat 

 exaggerated in these curves. 



Curves have been prepared for the Katha and Mesangan sections of the 

 Saretha group. These show that the latter section, consisting of larger canes, 

 only resembles the Sunnabile series in the number of leaf sheaths. In other 

 respects the curve approaches nearer to that of the 1916 measurements in the 

 Saretha group, it is higher and steeper than that in the Katha section. 



Lamina. 

 The leaf blade or lamina has been subjected to a rather more exhaustive 

 study than the leaf sheath, as it presents details of form which are absei\t in 

 the latter. In no part, of the plant is it more evident that a real difference exists 

 in the two groups in the length and shape of organs, and the elaboration of this 

 |)oint has taken a good deal of time. For one thing, the differences between the 



