3 io 



LECTURE XIV. 



9 10 a.m. In the case of Colocasia odora, in which the 

 grand period is much longer, the following results have been 

 obtained. 



Day I is the day on which the spathe opens. 



When the grand period extends over a considerable time, 

 as in the case of growing shoots for instance, the course of 

 the daily period is more regular. Dutrochet came to the 

 conclusion from his numerous observations on growing 'shoots 

 that the hour of the daily occurrence of the maximum excess* 

 of temperature is constant for any given plant, but that it is 

 different for different plants. 



Dutrochet determined the daily period of the evolution of heat by 

 shoots in the following cases. 



These observations were made upon plants in a saturated atmosphere 

 to prevent loss of heat by transpiration. 



