514 Theory of the Nutrition [BOOK in. 



various movements in plants, and it cannot be denied that he 

 was sometimes led into obscure and doubtful views, as for 

 instance when without any apparent connection he regarded 

 the inhalation of oxygen as a mechanical condition of the rising 

 of the sap and also of heliotropic curvatures, and that his 

 attempts at explanation were not seldom forced and impro- 

 bable ; but all this does not prevent it from being true, that an 

 attentive reader will still gain much instruction from his physio- 

 logical writings and be excited by them to examine for himself. 

 Dutrochet was a decidedly able man and an independent 

 thinker, who it is true was often led astray by his prejudices, 

 but at the same time manfully protested against the old tradi- 

 tional way of dealing with physiological ideas, and substituted 

 careful examination both of his own and others' investigations 

 for the accumulation and comfortable retailing of isolated ob- 

 servations which was then the fashion. After de Saussure's 

 ' Recherches chimiques ' Dutrochet's ' Memoires pour servir a 

 1'histoire anatomique et physiologique des vegetaux et des ani- 

 maux,' 1837, are without doubt the best production, which 

 physiological literature has to show in the long period from 

 1804 to 1840. If later botanists, instead of dwelling on his 

 faults, had developed with care and judgment all that was 

 really good in his general view of vegetable physiology, this 

 branch of botanical science would not have declined as it did 

 in the interval between 1840 and 1860. We shall discover 

 the greatness of Dutrochet as a vegetable physiologist by com- 

 paring his work above-mentioned with the best text-books of 

 the subject of the same time, those of De Candolle, Trevira- 

 nus, and Meyen ; not one of them comes up to Dutrochet's 

 Memoires in acuteness or depth. 



The three text-books just mentioned contained little or 

 nothing new either in facts or ideas on the subject of the 

 nutrition of plants ; all three were rather compilations of what 

 was already known, and differed from each other only in their 

 selection of material and in the form which each sought to give 



