PLANT REPRODUCTION 159 



spaces between the drainage are all filled so that after the 

 soil is watered and the seeds sown, there will be no settling 

 of the surface. No fresh manure should be used in soil 

 for seeds, for the roots as they develop are very delicate, 

 and burning will result. The soil should be sifted and the 

 seed bed should be made perfectly level. It is a good 

 practice to water the soil before the seeds are sown, so 

 there is an abundance of moisture in the bottom of the 

 box. Let the seed box stand several hours, or until the 

 surplus water has drained off ; stir the surface soil slightly 

 and sow the seeds. 



124. Seed sowing. Seeds should be sown evenly and 

 thinly enough so that the seedlings may have enough 

 light, and will not spindle and make a weak growth. No 

 definite directions as to thickness of sowing can be given. 

 Much will depend on the judgment of the sower. After 

 the seeds are sown, they should be pressed into the soil 

 with a smooth block, care being taken to clean the block 

 after each variety of seeds is sown, so that there may be 

 no mixing of species. A thin layer of soil should then be 

 placed over the seeds, using a soil mixture of one-half 

 sand and one-half leaf-mold. This light, porous mixture 

 will prevent the soil from crusting. The surface should 

 be moistened with a fine spray, and a pane of glass put over 

 the flat or pan, to prevent evaporation of moisture. The 

 glass should be covered with a newspaper, kept moist, to 

 exclude direct sunlight, and the flat or pan placed in such 

 a temperature as is required by the species. A tempera- 

 ture of 45 or 50 agrees with most species of annuals and 

 perennials. Tropical seeds demand a temperature of from 

 65 to 70. As soon as the seedlings begin to break through 

 the soil, the paper should be removed, and the glass tilted 

 a little to admit air. 



