physicians, they were compelled to compare together a great variety of native plants, and thus to exercise and perfect the faculty of apprehending differences of form. This mode of proceeding, arising out of medical requirements, directed the attention entirely to the individual form, which was also the chief thing required in the interest of pure science, and much more was thus gained than if these men had only followed the philosophical writings of Aristotle and Theophrastus. The Greek authors built their views on the philosophy of botany on very weak foundations; scarcely a plant was known to them exactly in all its parts; they derived much of their knowledge from the accounts of others, often from dealers in herbs. From this scanty material and from various popular superstitions had Aristotle formed his views on the nature of plants, and if Theophrastus possessed more experimental knowledge, he still saw facts in the light of his master's philosophical doctrines. If we succeed in the present day in extracting much that is accurate from the writings of Aristotle and Theophrastus, it was nevertheless well that the first compilers of herbals ceased to pay attention to them, and occupied themselves with accumulating descriptions of individual plants worked out by them-
- Beside the herbals mentioned in the text, which may be regarded as scientific works on botany, a considerable number of books on the signature of plants were written in the 16th and I7th centuries in the interests of medicine or medical superstition. It was believed that certain external marks and resemblances between parts of plants and the organs of the human body indicated the plants and the parts of them which possessed healing virtues. Pritzel mentions by name twenty-four works of the kind, which appeared between 1550 and 1697. The herbals also noticed the signatures, and even Ray has an enquiry into the subject.
- The fragments of Aristotelian botany which have come down to us are to be found translated from Wimmer's edition in Ernst Meyer's 'Geschichte der Botanik,' i. p. 94.
- Ernst Meyer (Geschichte der Botanik) gives a full account of Theophrastus, who was born at Lesbos A.C. 371 and died A.D. 286. An edition of his work 'De historia et de causis plantarum' was published by Theodor Gaza in 1483. See also Pritzel's 'Thesaurus literarum botanicarum.'