1913] Goodspeed : Germination of Tobacco Seed 203 



results of each observation. A circle drawn in lead pencil about 

 one group of one hundred seeds distinguished it in the matter 

 of keeping the records of duplicate tests. In every case there 

 was no preference given to the larger, better formed seeds in 

 arranging the seeds to be tested. On the contrary the relatively 

 few ill-formed seeds were included as they occurred, since one 

 of the primary objects of the investigation w^as concerned with 

 determining what proportion of viable seeds each plant normally 

 produces. The criterion of germination was the same as that 

 elsewhere noted (Goodspeed, loc. cit., p. 98). A number of tests 

 demonstrated the fact that 96.8 per cent of the seeds thus 

 decided upon as showing germination will give rise to vigorous 

 seedlings the development of which has been watched for two 

 weeks after germination. It seems certain that this percentage 

 would be higher if it were possible to eliminate the injurious 

 etfects of handling the very small germinating seeds, which are 

 difficult to pick up lightly. 



An even approximately standard germinating case was not 

 available. The finger bowls covered by the seed holders were 

 placed on sand in a shallow glass-covered case built on the top 

 of a greenhouse bench. Unfortunately strictly constant tempera- 

 ture conditions were not possible in this germination test except 

 toward the end of the experiments herein reported upon. At 

 the start of the experiments the temperature of the w^ater in 

 the finger bowls varied between 27° C for the average day tem- 

 peratures and 22° C for the night temperatures (cf. Garman, 

 1910). This amount of variation was somewhat cut down after 

 the end of two weeks and during the last month of the experi- 

 ments the temperature conditions under which germination took 

 place were very fairly constant at 25° C. 



(h) In Connection with Sulfuric Acid Treatment 



The work herein reported on that is connected with the effects 

 of treatment with sulfuric acid upon the germination of tobacco 

 seed is presented merely as preliminary with regard to more 

 detailed experiments which are at present in progress. The 

 value of sulfuric acid treatment has been established, however, 

 and this fact seems to warrant the inclusion of such experi- 

 mental evidence as is at hand as well as the methods employed 



