Page:History of botany (Sachs; Garnsey).djvu/267

 Rh this the example of Malpighi and Grew, did not make the knowledge of structure the sole aim in their anatomical investigations, 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, 'Vernünftige Gedanken von den Wirkungen der Natur,' Magdeburg (1723) and 'Allerhand nützliche 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