16 A History of Botany, 1860-igoo 



had not been the subjects of study in any detail — indeed 

 no methods had been devised for dealing with them. The 

 appropriation of carbon dioxide was held to be a form of 

 respiration quite as much as the true respiratory processes ; 

 the nature of the latter was not understood, and it was 

 held to be nocturnal only in its occurrence. True, specula- 

 tion had begun to be rife and inquiry was in the air, but 

 botanists stood on the threshold of an unknown territory 

 illuminated by hardly a single ray of light. 



By many others a still less satisfactory position was 

 taken up. Anatomical or histological conceptions were 

 made primary, and functions sought or imagined for each. 

 For instance, parenchyma was thought to have some 

 definite function as such, and consequently this hypothetical 

 function was suspected wherever parenchyma occurs. 

 The same sort of conception was applied to the stem — it 

 was thought necessary to assign separate functions to the 

 pith, the wood, the medullary rays, the bark, all of which 

 were held to be definite organs. No doubt it is possible 

 to see a relation in these structures to a division of labour, 

 but a severe allocation of each to some particular duty 

 went much further than was justified by the state of know- 

 ledge. The fundamental error in conception was a failure 

 to recognize the plant as an individual exhibiting unity of 

 purpose in its working. Instead, the cell was made the 

 unit, and inaccurate conceptions followed. It is rather 

 strange also to notice in the textbooks of the time what 

 a lack of proportion was shown in the treatment of physio- 

 logical subjects. It was not uncommon, for instance, to 

 find that descriptions of the ' rotation of sap ' in the cell 

 had as much space allotted to them as the whole story of 

 absorption and transmission of fluid ! 



The progress of classification was almost at a standstill. 

 The system of de Candolle was almost universally accepted 

 as a basis, and though Lindley in England, and Brongniart 



