EXPLANATION OF PLATES 



A special note is due the illustrations in this paper. The line drawings were 

 made by Miss Anna Hamilton and Miss Helen M. Gilkey. Special attention was 

 paid to accuracy in proportions and details. No attempt, however, was made 

 to represent the characteristic Nicotiana pubescence. The photographs require 

 no special mention save that sometimes the garden number given in the legend 

 does not correspond with that given on the label in the photograph. The dif- 

 ference is due to a change in system of numbering used in F3 and in subsequent 

 populations. In this paper, in order to avoid confusion, garden numbers from 

 the beginning have been made to conform to this change. The legends of 

 all the plates have been made more complete than is usual in order to facilitate 

 cross-reference and to enable the reader to grasp their essential significance more 

 readily. 



PLATE 55 



Fig. 1. Nicotiana Tabacum var. angustifoUa, U. C. B. G. 68/07. A typical 

 plant of angustifoUa at the height of its blooming period. The laterals over- 

 topping the central axis and the long-petioled stenophyUa form of leaf are 

 especially to be noted. The drooping of the leaves is very characteristic of this 

 variety. 



Fig. 2. Nicotiana Tahacum var. macrophylla, U. C. B. G. 22/07. A typical 

 plant of macrophylla at the height of its blooming period. Note especially the 

 stout laterals overtopping the central axis and the sessiUfolia type of leaf. 



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