PLANT PHYSIOLOGY. 



Temperature-stages may be purchased at prices from $7.00 upwards. 

 Various forms are figured in Goodale's Physiology, page 202, in Detmer. 

 421, in Verworn, 392. Very elaborate forms have been devised for special 

 researches. 



FIG. 8. TEMPERATURE-STAGE AND METRONOME. 

 One-fourth the true size. 



10. What effect is produced upon Protoplasm, as manifested in 

 its rate of movement, by presence or absence of light, and by varia- 

 tions in its intensity? 



Answer from the results of simple experiments invented 

 by yourselves (call them Experiment 2). 



/>Y careful to avoid t/ic influence of variations in Jieat. 



with other forms, with the result that it is found to be at least as accurate as any of 

 those made on the principle of warming a metal plate (while superior to most of them 

 is the ease and convenience with which temperatures may be reduced to zero), and 

 nearly, if not quite, as accurate as those using a circulation of hot water. 



