THE FRUIT AND THE SEED 99 



and bears no direct relation to the time at which the seeds 

 are set free from the parent plant. Seeds of the tomato 

 will germinate when the fruit is little more than half- 

 grown, and those of the pea will germinate when fit for 

 table use. Seeds of the lemon sometimes germinate 

 within the fruit. On the other hand, seeds of the thorn 

 (Crataegus) and juniper rarely germinate until the second 

 spring after their production. Seeds of many annual 

 and biennial plants, as the cereals, cabbage and the like, 

 may germinate as soon as set free by the parent plant, 

 but those of many annual weeds and of most trees and 

 shrubs will not germinate until some months afterwards. 



Seeds necessarily gathered immature will often ripen 

 sufficiently for germination if a considerable part of the 

 plant is plucked and cured with them. 



Germinating seeds in which the germination process 

 is stopped by undue drying are not always destroyed. 

 Germination may be resumed on access to water. Seeds 

 of different species differ widely in this respect. Those 

 of the parsnip and carrot cannot endure much drying 

 during germination, while those of the cereals may be 

 repeatedly dried at ordinary temperatures without de- 

 stroying their vitality. 



163. Immature versus ripe seeds. — Seeds not fully 

 grown lack a part of their normal food supply, and their 

 embryo is probably imperfectly developed. If capable of 

 germination, they rarely produce vigorous plants. As a 

 rule, the most vigorous plants come from fully-matured 

 seeds. Immature seeds, persistently used, may tend to 

 reduce vigor, and cause early maturity, dwarfing and 

 shortened life. In some over-vigorous plants, as the 

 tomato, slightly immature seed may tend to increased 

 fruitfulness. 



