CURRENT LITERATURE 



NOTES FOR STUDENTS 

 Temperature and respiration rate.— Blanc 1 has studied the effect of 



changes 



germinated 



and that of Palladia with etiolated seedlings of the same species. These 

 two investigators, although working with very similar material, came to very 

 different conclusions as to the influence of sudden changes of temperature 



ADIN 



upon the rate of respiration. 



temperature or from a high temperature to a medium temperature exciters the 

 respiration is considered doubtful on account of the fact that, previous to the 

 change in temperature, the seedlings had been cultivated at different tem- 

 peratures on sugar solutions. 



Blaxc worked with the embryos of Phaseolus vulgaris deprived of their 

 cotyledons, with the ends of etiolated seedlings of Vicia Faba, and with young 

 leaves of Secale cereale. The Vicia seedlings had previously been cultivated 

 on 10 per cent saccharose or 5 per cent glucose solutions. The Phaseolus 

 embryos and Secale leaves were used both with and without previous culti- 

 vation on ro per cent saccharose solution. Raising the temperature at which 

 the experiment was conducted invariably increased the rate of respiration, and 

 lowering the temperature always decreased the rate. After having undergone 

 one such change of temperature, samples of the material studied were returned 

 to the original temperature for a short period (15-30 mins.). It was found 

 that the rate of respiration during this second period at a given temperature 

 was higher than that during the first period whenever the temperature had 

 been raised during the intervening period, and lower whenever the temperature 

 had been lowered during the intervening period. 



In a third series of experiments, embryos of Phaseolus vulgaris and leaves 

 of Secale cereale were changed from one temperature to a temperature about 

 20 C. warmer or 20 C. cooler, and the rate of respiration was determined for 

 3 successive 20-minute periods at the new temperature in comparison with the 



experimen 



temperature sur la respiration des plantes. Rev. Gen. Bot. 28:65-79. 1916. 



'Ziegenbein, E., Untersuchungen iiber den Stoffwechsel und die Athmung 

 kemiender Kartoffelknollen sowie anderer Pflanzen. Jahrb. Wiss. Bot. 25:595-596. 



* Palladin, \V., Influence des changements de temperature sur la respiration 

 des plantes. Rev. Gen. Bot. 11:241-357, l899 . 



524 



