124 The Principles of Vegetable- Gardening 



sharply are supposed to have been good. It is also 

 tested by throwing the seeds into water, those which 

 sink being regarded as viable. These practices are not 

 to be recommended. 



1. The natural and normal limit of germinative vital- 

 ity is usually a specific character, peculiar to the indi- 

 vidual species. Therefore no general law concerning 

 the natural or normal limit of vitality can be enunci- 

 ated. Species of very close botanical affinity often 

 differ widely in this regard. In some instances, how- 

 ever, there are tolerably well-defined family traits, as, 

 for example, in the Cucurbitaceae (pumpkins, squashes, 

 melons, cucumbers), of which most of the species pos- 

 sess a rather high longevity, and likewise in the Le- 

 guminosae. Seeds of the Umbelliferae, on the other 

 hand (as parsnip, carrot, celery, parsley), have a rela- 

 tively low vitality, and this trait is probably associated 

 with the oily character of the seeds and fruits. This 

 natural longevity is not correlated with the normal 

 size of the seed. The minute seeds of tobacco, if per- 

 fect, grow well when seven or eight years old, but the 

 large seeds of castor bean may fail in two years. 



2. The loyigevity or vitality of seeds is determined 

 largely hy the conditions under which they grew. As a 

 rule, the most vigorous development of plant produces 

 the most perfect vitality of seed, although the product 

 of such seed may not be the most satisfactory for the 

 cultivator. Conversely, a poor season for the vegeta- 

 tion of any plant, or other untoward circumstance, by 

 causing a weak plant, produces seeds of impaired 

 vitality. Seedsmen are aware of this fact, and they 



