REQUIREMENTS OF TEMPERATURE. 7 



ful and convenient place for the storage of pots and boxes 

 of slow-germinating seeds. A more elaborate shed screen, 

 made of lath or slats, and containing seed-beds edged with 

 boards, is shown in Fig. 9. 



Various frames and covers are employed for indoor 

 seedage, but they are designed to regulate atmospheric 

 moisture and to control temperature. They are more 



9. Large shed sere en , with seed-beds. 



commonly employed in the growing of cuttings, and are, 

 therefore, described in Chapter IV. 



Requirements of Temperature. Variations in temperature 

 exercise less influence upon seeds than variations in moisture. 

 Yet it is important that the extremes of temperature should 

 not be great, especially in small, delicate or weak seeds. 

 Seeds will endure greater extremes of temperature when 

 dry than when moist. This indicates that germinating seeds 

 must be kept in a comparatively uniform temperature. For 

 this reason it is poor practice to put seed-boxes in a window 

 in full sunlight. Partial or complete shade serves the double 

 purpose of preventing too great heat and too rapid evapora- 

 tion. Various covered seed-boxes are used for the purpose 

 of maintaining approximately the required temperature, but 



