1912] 



Goodspeed: Nicotiana Hybrids 



99 



3. Total Germination and Discussion of Rates op 



Germination 



Under constant experimental conditions over 50 per cent of 

 the light-weight and medium- weight seeds germinated in less 

 than four weeks. Under the same conditions and during the 

 same period of time 40 per cent of the heavy-weight seeds ger- 

 minated (Shamel & Cobey, 1907, p. 58). 



There was fairl}^ regular diminution in the amount of 

 germination under these constant experimental conditions and 

 during this month, as the weight of the seeds increased. 



Under widely varying conditions of temperature and light, 

 the heavy-weight seed which had not germinated in the ger- 

 minating case gave an average germination of 38 per cent in 

 four weeks. Under these widely varying conditions and during 

 this period of time the light and medium weights of seed gave 

 an average germination of 18 per cent. 



Tlie final count, which includes germination in the genu in- 



