78 STtJDIKS IN INDIAN TOBACCOS. 



two varieties, unless such has been proved to be the case by actual 

 experiments. Under these circumstances we considered that it 

 would be best to arrange the Indian tobaccos in a provisional 

 scheme of classification based on easih^ recognizable characters 

 to facilitate identification and reference. The choice of the 

 characters on which to base the classification of the Indian 

 forms of Xicotiaaa tahacum was difficult owinof to the manner 

 in which the tj^pes grade into one another and form a series. 

 The most promising characters appeared to be habit, shape of 

 the leaf and the similarity or dissimilarity of the inflorescence 

 and lower leaves. It was finally decided to base the main 

 divisions on the leaf characters, using the habit for further 

 subdivisions. 



Of the fifty-one Indian types of N. tahacum, five ma}^ be 

 termed petiolate and are placed in one group. The petioles are 

 alwajT^s alate and the inflorescence leaves occasionall}'' appear 

 almost sessile, but there is no difficulty in separating the petiolate 

 forms from the others. Only in the case of type VII it must 

 be noted that a few of the median leaves appear stalked. In all 

 the leaves the lamina is much reduced and in a few the reduction 

 is carried so far that only a very narrow strip of lamina runs 

 down the petiole. One of these has been chosen for the photo- 

 graph. As, however, the sessile character of most of the leaves 

 is clear, the occasional presence of the leaves in which a petiole 

 is simulated should present no difficulty. Whether the leaves 

 termed " petiolate " above should really be considered as leaves in 

 which the lamina is reduced to a minimum does not concern 

 the classification, as tlie stalked character of the leaves in these 

 types forms an easy mark of distinction. The group of forms 

 with sessile leaves is subdivided into three classes depending on the 

 character of the leaves : (A) forms with long narrow leaves, (B) 

 forms with leaves broad in the centre and tapering towards both 

 ends, (C) forms with leaves broad and elliptical which do not taper 

 at either end. These distinctions hold well on the whole, al- 

 though both in (B) & (C) there are one or two t^qjes which are 

 not absolutely typical (see type XXIII in (B) and type 



