94 White. 



327. N. glutinosa L. U. C. Bot. Garden 1909, Comes' Mon. 

 (p. 24) Sp. 3. Coastant from selfed seed for 3 years. 



331. N. paniculata L. U. C. Bot. Garden 1909, Comes' Mon. 

 (p. 25), Sp. 4. Constant from selfed seed for 3 years. 



332. N. sylvestris Spe^. et nob. (Nova, sp.) IT. C. Bot. Garden 

 1909. Comes' Mon. (pp. 34—35). Sp. 19. Constant. 



b) Number of plants grown. 



This investigation of the inheritance of fasciation in species of 

 Nicotiana is based on data from studies of about 5,000 plants, grown 

 over a period of five years, and under several distinct physiological and 

 geographical environments. A nearly complete list of the different 

 species, races, families and hybrids, together with the exact number of 

 each grown, the year and the environment are given in Table 1. 



c) Methods. 



All plants used in these experiments were grown as nearly as 

 practicable under the same external environmental conditions. Plants 

 for comparative study were often grown side by side. After each 

 operation in making crosses, all instruments were carefully cleansed in 



95 per cent alcohol. Pollen was used only from unopened flowers. 

 The technical work was always personally looked after. The methods 

 used in the cytological phase of this investigation are described in an 

 earlier paper (White 1913). 



Tabulation. Data were collected on each plant and tabulated 

 separately. The character on which most of the studies were made 

 were: — extent of fasciation in the main axis, number of leaves per 

 plant, number of floral parts per whorl. 25 flowers from each plant 

 were taken and th« number of parts per wliorl for each flower was 

 recorded separately, and in such a manner that all the whorls per 

 single flower, remained identifiable and their correlation could be shown. 

 Minor abnormalities of all kinds, such as calycanthemy, pistillody of 

 the stamen, united filaments (cohesion), abnormally distorted anthers, 

 petalody of the stamen, deformed styles and stigmas, cohesion or fission 

 in leaves, were recorded for each flower and plant. In presenting in 

 tabular form, the mass of data thus accumulated, two types of frequency 

 tables are used, each of wliich shows the variability of the fasciated 

 character expressed in terms of numerical-plant-organ alterations, as for 

 example, one flower may have 8 sepals, 10 petals, 12 stamens, and 



