272- 



(8) Influences of latitude upon s|)routing. Corn from South Caro- 

 lina and Alabama ^as compared with that from Ithaca, X. Y. 



(9) Variations in duj^licate tests under like conditions. 



(10) Comparisons of results of seed tests Avith results of actual 

 sowing in the field. 



(11) Impui'ities in sainples of garden seeds. Over 100 packages 

 were examined, for 90 of which the results were tabulated and com- 

 pared. " Xo evidence of adulteration was found, and weed seeds 

 were feAv and unimportant." " The impurities were very largely 

 immature and imperfect seeds." They averaged by number 2.76 per 

 cent, and by weight 1.38 per cent. 



General summary. — 1. The results of a seed test depend very largely upon the 

 known conditions under which the test is made : 



(1) Variations in temperature may cause variations in rapidity of sprouting. 



(2) An essentially constant temperature of about 74° gives quicker results 

 than an ordinarily variable temperature of a similar mean. 



(3) Probably any constant temperature gives quicker results than a variable 

 temperature of which the mean is the same as thi^ constant temperature. 



(4) As the mean temperature lowers, sprouting, as a rule, becomes slower. 



(5) In some instances greater rapidity of sprouting, due to a constant tera- 

 Ijerature of 74°. does not appear to be correlated with greater per cent of total 

 sprouting. In beans, however, greater per cent of sprouting appears to follow 

 greater rapidity of sprouting. 



(G) There is probably a tolerably well-defined optimum temperature for each 

 species of plant, in which best results from seed tests can be obtained. This 

 limit is not closely determined for njost garden seeds. 



(7) The quantity of water applied to seeds may determine both the rapidity 

 and per cent of sprouting. 



(8) A comparatively small amount of water gives quickest and largest results. 



(9) Greater quantities of water than are required for best results lessen 

 rapidity and per cent of sprouting, either by causing the seeds to rot or by 

 retarding germination, or by both. 



(10) The soaking of seeds in water before planting does not appear to hasten 

 sprouting if the planting time is reckoned from the time at which the seeds are 

 put to soak. But if planting time is counted from the time of placing the seeds 

 in soil, quicker sin-outirgs are the result This niethcd is incorrect, however. 



(11) Soaking of seeds does not appear to influence amount of sprouting. 



(12) The results of soaking appear to vary in different species. 



(13) The character of soil in which the test is made may influence the results, 

 both in rapidity and per cent of sprouting. 



(14) Light has great influence upon the sprouting of the seeds of some species. 



(15) When light has any influence it retards or wholly prevents sprouting. 



(16) The effects of light upon sprouting are different in different species. 



(17) The weight of the seed is often a tolerably accurate measure of its 

 viability, as determined both by rapidity and per cent of sprouting. 



(18) As a rule, heavy seeds germinate better than light ones. 



(19) Seeds of different species may vary in sprouting in reference to weight. 



(20) The color of the seed in some cases is a tolerably accurate measure of 

 rapidity and per cent of sprouting. 



(21) When there is any variation in viability in reference to color, it is 

 usually found that the stronger sproutings occur in the darker colored seeds. 



(22) The relative values of seeds of different colors vary with each species, or 

 sometimes with each sample. 



