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 but without a mirror, an instrument which must have served therefore for observing with the light from above on an opaque surface; the objective was a simple lens. But to magnify objects more strongly, he says that he used a simple instead of this compound instrument, as was more the custom at the time. Like a true amateur Wolff submitted all sorts of small and delicate objects to his glass, without examining any of them thoroughly and persistently. His phytotomic gains were small; he observed for instance that starch-flour (powder) consists of grains, but believed from the way in which they refracted light that they were small vesicles filled with a fluid; yet he satisfied himself that these grains are already in the grains of rye and therefore not produced in the grinding. He laid thin sections of portions of plants on glass which was too imperfectly polished to allow of his seeing anything distinctly. His pupil Thümmig in his ‘Meletemata’ (1736) addressed himself to the subject with still less skill. By the case of these two men we may see plainly that want of success was due much less to the imperfectness of the microscope than to unskilful management and unsuitable preparation. But Wolff and Thümmig at least endeavoured to see something for themselves of the structure of plants; a famous botanist of the time, Ludwig, plainly never made a similar attempt, for in his ‘Institutiones regni vegetabilis’ (1742) he speaks of the inner structure of the plant in the following manner; ‘Laminae or