ABSORPTION OF GASES. 77 



Madia, 72 hours at 13 C. 



absorbed 15*83 c.c. of oxygen, 

 exhaled 11*94 c.c. of carbon dioxide. 



Oudemans and Rauwenhoff found that the amount of 

 oxygen absorbed varied in the case of the seeds of different 

 species of plants, and that it diminished gradually during the 

 process of germination. 



Lory shewed that phanerogamic plants which contain 

 but little chlorophyll, such as various species of Orobanche, 

 and Neottia Nidus-avis, absorb oxygen under all circum- 

 stances : 



A flowering plant of Orobanche Teucrii absorbed in thirty-six hours 

 4*2 c.c. of oxygen for every gramme of its weight : a plant without flowers 

 absorbed 2*68 c.c. of oxygen for every gramme. 



but according to Drude the exhalation of oxygen by Neottia 

 is greater than the absorption when the plant is exposed to 

 intense light. 



De Saussure ascertained that flowers absorb oxygen : 



Thus, 



flowers of Cheiranthus incanus absorbed iro vols. of oxygen in 24 hours, 



double flowers of 77 



flowers of Tropceolum majus ,, 8*5 



Datura arborea 9*0 



Passiflora serratifolia 18*5 



,, Daucus Carota 8'8 



the volume of the flower being taken as unity. 



he found further that the essential organs of the flower are 

 those which absorb the largest proportion of oxygen, and that 

 .the andrcecium does so more actively than the gynaeceum, 



Cucurbita Melo-Pepo. 



The volume of the organ being taken as unity, the organs of the 

 flowers absorbed the following quantities of oxygen : 



absorbed in 10 hours 



Staminate flower 7-6 vols. O. 



Pistillate 3-5 



Anthers .:. . . ^ 'J.<; 117 



Stigmas ... 47 



