1913] Goodspeed: Germination of Tobacco Seed 209 



from the treatment of tobacco seed with 70 per cent or 80 per 

 cent sulfuric acid for varying lengths of time in hastening 

 germination and particularly in increasing its amount. It is 

 hoped that the results of further experiments in this connection 

 may be reported upon in the near future. 



V. THE RELATION BETWEEN THE AGE OF SEED AND 



ITS VIABILITY 



The following tables deal Avith the results of some thirty-five 

 germination tests carried through in the effort to determine in 

 a preliminary fashion the relation between the age of tobacco 

 seed and its viability. As will be seen in only one case — i.e. 

 110/05 — was it possible to test any one species as to the viability 

 of the seed of consecutive years from the year first grown in the 

 U. C. B. G. to the seed of the present year. In other cases — • 

 i.e., 22/07 — the tests represent seed of an uninterrupted series of 

 years but the seed of the first year or so as grown in the U. C. 

 B. G. is missing. In still other cases — i.e., 53/03 — tests are lack- 

 ing for the oldest seed and the series is also interrupted. 



Table 3 below represents a general compilation by years of 

 the results of the various tests. Apart from the remarkably high 

 percentage of germination among the six, seven, and eight-year- 

 old seed the most interesting points brought out in table 3 have 

 to do with the germination of the .V. acuminata-vdrieties in 

 general, the low percentage of germination of 22/02 more than 

 two years old, and the low germination percentages in many 

 eases for the seed gathered in 1910. 



AVith reference to this last point no explanation can be 

 offered except that during the season 1910 conditions for maxi- 

 mum growth and development were not so distinctly favorable 

 as in the preceding year or in the two following years. Actual 

 climatic conditions do not seem to liavc differed greatly from 

 the average, but the garden records show that the parent strains 

 of tobacco — .V. Taftacwm-varieties in particular — did not germi- 

 nate as rapidly or as fully in 1011 as normally. A point of this 

 sort in connection with the j^ropagation of material connected 

 witli hy])ridiza1ion experiments on the plant side iii.iy in general 



