CHAPTER VIII 



THE DEVELOPMENT OF THE MODERN IDEA 

 OF THE CATABOLIC PROCESSES AND THE 

 INTERNAL ENERGY RELATIONS OF PLANTS 



One of the most remarkable features of the early part 

 of the period 1860-1900 was the confusion that had 

 arisen on the subject of respiration. So far back as the 

 time of Ingenhousz and De Saussure clear ideas of the 

 chief external facts had been obtained and up to a certain 

 point satisfactorily interpreted, while Dutrochet, as late 

 as 1837, had put forward a comprehensive statement of 

 its nature and showed that the process is fundamentally 

 the same in animals and plants. But shortly afterwards 

 misconceptions had arisen, the two gaseous interchanges 

 associated respectively with respiration and photosynthesis 

 had been confused, and the idea had gained ground that 

 while the latter of these processes was carried on in the 

 light, the former replaced it during darkness. Hence sprang 

 the view that the respiration of plants included them both, 

 so that diurnal and nocturnal respiration were spoken of. 

 Liebig unfortunately went further than this and denied 

 explicitly the existence of respiration in plants in the true 

 sense. The weight attached to his opinion unhappily put 

 back the clock for quite a quarter of a century, in spite of 

 the protests of several observers, particularly of Garreau 

 in 1851. 



In i860 the view of a kind of complementary inter- 

 change marking diurnal and nocturnal respiration was very 

 generally accepted, and it held its position for a number 

 of years subsequently, as may be seen by the standard 



D d2 



