1913] Goodspeed: Germination of Tobacco Seed 213 



be noted on a given year, but its full significance is lost unless 

 a little of the seed is germinated each year under controlled con- 

 ditions and in a manner which makes possible more or less exact 

 germination counts. In this connection it may be said that the 

 possession of such records would have been greatly appreciated in 

 connection with the results of certain experiments reported on 

 in a previous communication (Goodspeed, 1912, pages 87-117). 

 The general low germination of the seed gathered in 1910 is 

 further brought out in table 4 below. This table is a different 

 expression of the results set down in table 3. It gives the average 

 per cent of germination for each of the eight years in the case 

 of all the seed of each year germinated and thus is not an accu- 

 rate expression of the relative amounts of germination in each 

 case. In the case of 1912 tests the results of the tests with the iV. 

 ac?rmf)mia-varieties — 53/03, 192/08, and 150/07 — have not been 

 included, though appearing in table 3, since their extremely low 

 percentage of germination seems to show that other factors have 

 entered in to affect the results which are thus not typical. The 

 low germination of the seed of 1910 is again seen in table 5, 

 which is self-explanatory. 



These tables show the rather surprising viability of relatively 

 old tobacco seed (cf. Hayes, 1912, p. 3). The percent of germina- 

 tion in the case of eight-year-old seed of 110/05 or five-year-old 

 seed of 22/07 makes it seem probable that twelve and possibly 

 fifteen-year-old seed of N. Tabarum-Y&r\et\eH would germinate 

 to a certain extent at least — i.e., that deterioration as to viability 

 is a gradual process. The germination of the seed of 22/02, on 

 the other hand, makes it seem at least possible that there is a 

 more or less sharp end point as to the age limit of viability and 

 that after being kept a year or two more the seed of 1905 of 

 110/05 may fail to show any germination. As will be seen 

 in table 3 the 1909 seed of 22/02 germinated to the extent of 

 39 per cent, while among the seed of the same species one year 

 older only one seed in 200 germinated and only six seeds germi- 

 nated among 200 that were two years older. There is tlicn, in 

 the case of 22/02, a sharp drop in viability from nearly 40 per 

 cent to not over 5 per cent in one year as the seed is kept beyond 

 four years. At the end of the tests this older seed of 22/02 was 



