Phytotomy in the Eighteenth Century. 247 



this the example of Malpighi and Grew, did not make the 

 knowledge of structure the sole aim in their anatomical in- 

 vestigations, but sought it chiefly for the purpose of explaining 

 physiological processes. The food and circulation of the sap 

 of plants were more and more the prominent questions, and 

 Hales showed how much may be done in this direction even 

 without the microscope ; the interest therefore of the few, who 

 like Bonnet and Du Hamel occupied themselves almost entirely 

 with vegetable physiology, was concentrated on experiment. 



Others who knew how to use the microscope, as the Baron 

 von Gleichen-Russworm and Koelreuter, were drawn away from 

 the examination of the structure of vegetable organs by their 

 attention to the processes of fertilisation and especially of 

 propagation. The real botanists, according to the ideas of the 

 time, and specially those who belonged to the Linnaean school, 

 considered physiological and anatomical researches generally 

 to be of secondary importance, if not mere trifling, with which 

 an earnest collector had no need to concern himself. That 

 Linnaeus himself thought little of microscopical phytotomy is 

 sufficiently shown by what has been said of him in the first 

 book. 



It is not worth while to notice each of the few small treatises 

 on the subject which appeared towards 1760, for they contain 

 nothing new ; a few examples will show the truth of the 

 opinion here expressed on the general condition of phytotomy 

 at this time. 



We first of all encounter a writer, whom few would expect 

 to find among the phytotomists, the well-known philosopher 

 Christian Baron von Wolff, who in his two works, ' Verniinftige 

 Gedanken von den Wirkungen der Natur,' Magdeburg (1723) 

 and 'Allerhand niitzliche Versuche,' Halle (1721) gives here 

 and there descriptions of microscopes and discusses subjects 

 connected with phytotomy. This he does more particularly in 

 the latter work, where he describes a compound microscope 

 with a focussing lens between the objective and the ocular 



