PROPAGATION OF PLANTS. 211 



5. Light. 



EXPERIMENT 24. (a) Soak a number of different kinds 

 of seeds for a few hours and divide each kind into lots. 



(b) Place each lot on a square of moist flannel laid 

 upon moist sand, and cover with a glass tumbler. 



(c] Now cover one of these tumblers with a heavy 

 paper cone, the inside of which has been blackened by 

 simply holding it over a lighted lamp. 



(</) Watch the seeds in the uncovered tumbler. As 

 soon as any growth is shown, remove the paper cone 

 from the other tumbler, and compare the growth made 

 in the dark with that made in the light for each kind of 

 seeds. 



(e) Is light a necessary condition for germination ? 



6. Other Conditions. 



EXPERIMENT 25. (a) Soak for a few hours a number 

 of peas and Lima beans. Plant a definite number of 

 each kind of these soaked seeds at the same time in 

 moist sand at various depths, from one-half inch to four 

 inches, labeling as to depth. 



(b) Note carefully the appearance of each kind of 

 seedlings planted at the various depths. 



(c) Within a few days after the appearance of the first 

 seedlings, observe (i) the growth made by the peas 

 planted at the various depths, and compare; (2) that 

 made by the beans at the various depths; (3) the relative 

 growth made by the peas and beans. 



(</) Does the depth of planting have any effect upon 

 the time of germination ? Upon the certainty of germina- 

 tion ? By what external conditions is the germination 

 influenced ? What relation does the development of the 

 seedlings themselves bear to the depth of planting? 



IV- Treatment of Fine Seeds. 



Where practicable, very small seeds should 

 be sown indoors and given special care. 



