64 



CHAPTER III. 



DISCUSSION OF RESULTS. 



§ 11. C m p a r i s n o f t h e r f s u ] t s w i t h t h u s e o f 

 p r e V i us i n v e s t i g a t i o n s. 



In § 2 a survey has been given of the observations of 

 the influence of température upon geotropism. which hâve 

 been published up to the présent. In the first phace the 

 results ùbtained by Czapek and Bach mentioned there 

 must be compared hère with my own results. 



Czapek ') used germlnating roots of lAipinus albiis and 

 found, that the presentation-time did not dépend upon 

 températures between 15° C. and 30° C, that it rose 

 slowly at higher températures and increased rapidly below 

 15° C. Bach^) on the other hand, using seedlings of Vicia 

 Faba, found, that between 14° C. and 35o C. température 

 had a constant, distinct influence upon the presentation- 

 time, causing it to diminish between 14° C. and 30° C, 

 and to increase slowly at still higher températures. 



As to my own results, the table in § 9 shows vei'y 

 clearly, that from 0° C. to 30° C. the presentation-time 

 continually decreases, and at higher températures it increases 

 slowly at first and later more rapidly. 



Thèse results concerning presentation-time are generally 

 in harmony with those obtained by Czapek and Bach, 

 yet it remains an open question, why Czapek did not 

 flnd a decrease of the presentatidn-timc^ between 15° C. 

 and 30° C. It may be that tho (■xi)lanati(in lies in the 



1) F. Czapek, 1898. 



2) H. Bach, 1907. 



