36 



PRACTICAL COURSE IN BOTANY 



Experiment 29. What temperature is most favorable to germi« 

 NATION ? — Put half a dozen soaked beans on moist cotton or sawdust in 

 three wide-mouthed bottles of the same size or in germinators arranged as 

 in Figs. 48, 49, the seed also being selected 

 with a view to similarity of size and weight. 

 Keep one at a freezing temperature ; the 

 second in a temperature of 15° to 20° C. 

 (see Appendi.x for Fahrenheit equivalents) ; 

 and the third, at 30° C. If a place can 

 be found near a stove or a register, where 

 an even temperature of about 125° F. 

 is maintained, place a fourth receptacle 

 there. Observe at intervals of twenty- 

 four hours for a week or ten days, keeping 

 the temperature as even as possible, and 

 maintaining an equal quantity of moisture 

 in each vessel. Make a daily record of 

 your observations. What temperature do 

 you find most favorable to germination ? 



Figs. 48,49.— Home-made ger- 

 minators : 48, closed ; 49, showing 

 interior arrangement. 



Experiment 30. At what temperature do seeds lose their vital- 

 ity ? — Place about two dozen each of grains of corn, beans, squash 

 seed, and castor beans, with an equal number of plum or cherry stones, 

 in water, and heat to a temperature of 150° F. After an exposure of 

 ten minutes, take out -six of each kind and place in germinators made 

 of two plates with moist sand or damp cloth between them, as shown 

 in Figs. 48, 49. Raise the temperature to 175° F., and after ten minutes 

 take out six more of each kind of seed and j^lace in another germinator. 

 Raise the water in the vessel to 200°, take out another batch of seeds; 

 raise to the boiling point for ten minutes more, and plant the remain- 

 ing six of each lot. Number the four germinators, and observe at in- 

 tervals of twenty-four hours for two weeks. The harder kinds should be 

 kept under observation for three or four weeks, as they germinate slowly. 



Try the same experiments with the same kinds of seeds at a dry heat, 

 using a double boiler to prevent scorching, and record observations as before. 



Experiment 31. Time required for germination. — Arrange in 

 germinators seeds of various kinds, such as corn, wheat, peas, turnip, apple, 

 orange, grape, castor bean, etc. "Clip" some of the harder ones and keep 

 all the kinds experimented with under similar conditions as to moisture, 

 temperature, (^tc, and record the time required for each to sprout. What 

 is the effect of clijiping, and why ? 



Experiment 32. Are very young or immature seeds capable of 

 GERMINATING ? — Plant some seeds from half-grown tomatoes, and grains 



