370 CHANGES OF ORGANIC MATTER IN THE PLANT. 



a given period of time. There is little doubt that this refusal 

 of the resting part to start is an inherited trait connected in 

 some way with the protection of the plant against untoward 

 influences. 



977. Respiration is accompanied by an evolution of heat. 

 The flowers of the melon and tuberose were examined by Saus- 

 sure, who found that in the opening of the former there was 

 an elevation of 4 to 5 C., in that of the latter, .3. Caspary 

 detected a noticeable rise of temperature in the opening flowers 

 of Victoria regia, and the same has been observed in flowers of 

 species of Cactus. 



978. In those cases where it is possible to examine an organ 

 in which the process of respiration is rapid, as in a compact 

 cluster of flowers of Aracese, the difference between the tem- 

 perature of the air outside and that inside the spathe is ver} r 

 marked. 



979. The following results by Senebier, obtained by two 

 methods of experimenting, are very instructive, showing the 

 remarkable and rapid changes of temperature in such cases. 

 The plant in this instance was Arum maculatum. 



Temperature of air. Temperature of spathe. 



16.1 



17.9 



19.8 



21. 



21.8 



21.2 



18.5 



15.7 



14.1 



Even higher differences have been observed. 



980. Light is produced during the growth of certain of the 

 lower fungi under certain conditions. The phenomenon called 

 phosphorescence is not known in any of the higher plants. 1 

 According to Fabre, it is associated with the absorption and 

 consumption of ox}*gen, and the evolution of carbonic acid. 



981. Intramolecular respiration. Under certain circumstances 

 plants can continue to give off carbonic acid when no free 

 oxygen is supplied, and when they are kept in an atmosphere 



1 For an account of supposed cases of luminous flowers see Balfour's Class 

 Book of Botany, 1854, p. 676. 



