LONGEVITY 71 
show. Sturtevant mutilated the kernels of a Flint Corn and the 
seeds of Beans and found the percentage of germination much 
reduced in each case. 
Seeds collected while immature usually show a low percentage 
of germination and their embryos grow slowly. In the case of 
Rye, seeds have been harvested at different stages of their devel- 
opment and, after similar treatment in respect to drying and 
storage, the percentage of germination and vigor of embryos de- 
termined. In the milk stage five per cent germinated, while in 
the dry ripe stage eighty-four per cent germinated. The embryos 
of the dry ripe seeds were much more vigorous in growth than 
those of the immature seeds. Tomato seeds, while still green and 
not more than two-thirds the weight of mature seeds, may be 
germinated, if properly cured, but the plants produced are likely 
to be weak. The germination of unripe seeds has been given 
considerable attention by Sturtevant, Arthur, and Golf. 
Experiments? with seeds of the Radish, Sweet Pea, Cane, Rye, 
Oats, and Cotton have shown that better stands in the field and 
more vigorous and better vielding plants are secured by using 
only the heavier seeds. 
The vitality and vigor of seeds depend very much upon the 
methods of storing. Seeds are more easily killed by extremes of 
temperature when wet. Seeds stored where there is considerable 
moisture may start to germinate, and then die. Seeds, massed 
together before they are well dried, become moist and often so 
warm that the embryos are injured. On the other hand, when 
stored in rooms where the air is warm and extremely dry, seeds 
may lose moisture so rapidly that the embryos are killed. A 
storage room should be cool but above freezing, and dry, although 
not excessively dry. Until the seeds are well dried, they should 
not be massed together, but so arranged that the air can circulate 
about them. Thus methods of storing seed Corn and other seeds 
must reckon with a number of factors which affect the vitality 
and vigor of seeds under storage conditions. 
Longevity. — The vitality and vigor of seeds depend much 
upon their age. Seeds in excellent condition and stored by the best 
methods finally lose their vitality, due to the coagulation of their 
protoplasms, too much drying, or some other factor not under- 
1 American Naturalist, pp. 806 and 904. 1895. 
2 Farmers’ Bulletin 676, U.S. Dept. of Agriculture. 
