6 STUDIES TN INDIAN TOBACCOS. 



produced in tobacco by the soil and the general climatic conditions 

 both on the quality of the crop and also on the form of the plant. 

 It is clear that in order to obtain reliable evidence on the charac- 

 ters of the plant, and also on the inheritance of these characters, 

 one of the first conditions is to prevent any possible contamination 

 of the cultures. 



The first diflicult}^ experienced in growing a large number 

 of pure cultures is concerned with the raising of the seedlings. 

 As mentioned above, the ryots grow their seedlings in raised 

 seed beds. This, however, is clearly impracticable in the case of 

 several hundred cultures. In the first place, the seeds of tobacco 

 are so small that they might be carried from one bed to another 

 by wind, earthworms, rain or by careless workmen. In the 

 second place, some of the seeds would not germinate when sown, 

 but would come up during the following years, thereby contaminat- 

 ing the land for subsequent nurseries. The vitality of tobacco 

 seed is well known and in the United States the seed is often 

 kept several years. At Piisa, in 1905, some tobacco was allowed 

 to go to seed in one of the fields, and a certain amount of seed 

 found its way into the soil. Every year stray seedlings have 

 been noticed on this site and also on land at a lower level which 

 receives the surface drainage of the field in question. The 

 practice adopted at Piisa is to raise the seedlings in large boxes and 

 every precaution is taken to collect the earth and leaf mould from 

 places where contamination by stray tobacco seed is impossible. 

 The boxes are made up about six weeks before sowing and 

 kept moist so as to cause any chance seeds to germinate. So far 

 no tobacco seedlings have been found in the boxes prior to sowing. 

 The boxes are sown one at a time and the sower has to wash his 

 hands before sowino^ another box. After sowino- each box it is 

 immediately removed to the shade of trees till the seedlings 

 appear and up to planting time the boxes are enclosed in a wire 

 .netting fence to keep off animals and are watched day and night. 

 Precautions are taken during the process of thinning to prevent 

 admixture. The boys who do this work have to wash their hands 

 after finishing each box, as otherwise a few ungerminated seeds 



