INTRODUCTION 17 



baceous plants. Variation in length and intensity of the rest period 

 is greater between. species than within species. Etherization tends 

 to stimulate seeds into early growth and to increase the percentage 

 of total germination. Soaked and stratified seeds are more strongly 

 affected by ether than are dry seeds. A 12-hour exposure to ether 

 seems the most favorable dose to force seeds to germinate. 



28. Handling fleshy fruit seeds. Seeds of many fruits 

 must be freed from their fleshy or pulpy coverings before 

 they can be stored or planted. When there is no danger 

 of injury to them the fruits may be crushed or ground. 

 For instance, apples are so treated, the pomace mixed 

 with water and allowed to stand until the pulp has par- 

 tially fermented. The process requires a week to two 

 or three, depending mainly upon the temperature and the 

 character of the pulp. The seeds become separated from 

 the pulp and sink to the bottom. An occasional vigorous 

 stirring aids the process of separation. The pulp is fi- 

 nally poured off, the seeds collected, re-washed and dried. 



Soft fruits, such as blueberries, raspberries, strawber- 

 ries, and cranberries, are often treated in this way, though 

 they are perhaps as often handled like tomatoes, cucum- 

 bers, melons and other fruits, merely crushed under water 

 and then washed, the pulp being skimmed off and the 

 seeds allowed to settle. 



Sometimes the separation requires chemical treatment 

 to get rid of unnecessary membranes. For instance, the 

 membranes of persimmon seeds may be easily removed 

 after a soaking in weak caustic potash solution (a stick 

 to a pailful of water). 



Fresh ashes, lime and lye are of great help in freeing 

 many seeds of their resinous coverings. 



29. Points to remember about seeds. In Bulletin 58 

 of the Bureau of Plant Industry, J. W. F. Duvel writes 

 in substance as follows, except where brackets are used : 



A. Seeds are living organisms and must be properly treated to get 

 good results when sown. [They are dormant creatures. Or to use 

 an analogy, they are combined physical and chemical laboratories 

 which need only the proper conditions of moisture, heat and oxygen 

 to get them in operation.] 



