C. A. BARBEll 18^ 



it is perhapfcj worth while drawing attention here to the continued resem- 

 blances between the Katha section of the Saretha group and the wild Saccharum 

 spoHtaneum, and also to the transitional position so often seen of the Mesangau 

 section between the Katha and Sunnabile varieties. This would suggest a 

 line of evolution along which the cultivated sugarcane has been selected, having 

 its origin in a primitive form somewhat similar to a Katha variety, and passing 

 through some such form as a Sunnabile variety, already differentiated to a 

 certain extent and in some respects approaching the higher forms of cultivated 

 canes. 



(9) Ligular processes. These are upward scarious extensions of the edges 

 of the leaf sheath on either side of the base of the lamina, provided with a 

 rudimentary fibrovascular system, and are usually most prominent on the inner 

 margin of the sheath. They are clearly connected with the ligule which passes 

 into them at its edges and this suggests that the hgule is morphologically an 

 overlapping portion of the leaf sheath at its point of junction with the lamina. 

 The Katha varieties usually have well developed hgular processes. They 

 occur as long, sharp teeth, usually reaching an inch in length and occasionally 

 extending to double that length, when they form a striking and characteristic 

 feature. They are not usually present in the Mesangan section, althou^^h 

 Ganda Cheni has been noted as having occasional hgular processes up to half 

 an inch in length. In the Sunnabile group they are reduced to the usual blunt 

 angle, which soon becomes scarious, owing to the notching in the margin where 

 the sheath and lamma unite. 



(10) Ligule. This is treated here because of the possibility indicated 

 above of its being pai-t of the leaf sheath, and its intimate relation to the h^^ular 

 processes. It is narrow in both groups, although varWng a httle in this respect 

 in the Mesangan section and the Sunnabile group. In the Katha section the 

 ligule is usually flat or slightly depressed in the middle of its upper margin 

 and deeply depressed on its lower. In the middle it is distinctly broader than 

 at the edges and there is often a small triangular or diamond-shaped portion 

 here which is termed a lozenge, but this is not always present. The hgule in 

 the Mesangan section is flat or arched above and deeply depressed below. 

 There is usually a lozenge, although this is sometimes absent. The t}T[ncal 

 ligule of Sunnabile varieties is arched above, often with a flat depression iii the 

 middle and slightly depressed below. The two margim are often nearly 

 parallel and the lozenge is thus absent. 



The setae on the upper margin of the hgule present more striking differences, 

 as is often the case with hairs and hair-hke structures. They are extremely 



