222 Introduction. [BOOK n. 



seventeenth century, endeavouring by earnest reflection to 

 apply the powers of the mind to the objects seen with the 

 assisted eye, to clear up the true nature of microscopic objects, 

 and to explain the secrets of their constitution. If we compare 

 the works of these men with the utterances of the systematists 

 of the same period on the relations of form in plants, we can- 

 not fail to see how superior the matter of the former is in 

 intellectual value. This appears most strikingly when we put 

 what Malpighi and Grew tell us of the construction of the 

 flower and fruit side by side with the knowledge of Tournefort, 

 Bachmann, and Linnaeus on the same subject. 



This enhancement of the mental capacity of the observer by 

 the microscope is however the result of long practice; the 

 best microscope in unpractised hands is apt soon to become 

 a tiresome toy. It would be a great mistake to suppose that 

 progress in the study of the anatomy of plants has simply 

 depended on the perfecting of the microscope. It is obvious 

 that the perception of anatomical objects must grow more dis- 

 tinct as the magnifying power of the instrument is increased, 

 and the field of sight is made brighter and clearer, but these 

 things by themselves would not add much to real knowledge. 

 In examining the structure of plants, as in every science, it is 

 necessary to work with the mind upon the object seen with the 

 eye of sense, to separate the important from the unimportant, 

 to discover the logical connection between the several percep- 

 tions, and to have a special aim in the examination ; but the 

 aim of the phytotomist can only be to obtain so clear an idea 

 of the whole inner structure of the plant in all its connections, 

 that it can be reproduced by the imagination at any moment 

 in full detail with the perfect distinctness of sense-perception. 

 It is not easy to attain this end because the more the micro- 

 scope magnifies, the smaller is the part of the whole object 

 which it shows ; skilful and well-considered preparation is 

 required, careful combination of different objects and long 

 practice. The history of phytotomy shows how difficult a task 



