42 



own sake, and not merely on account of their usefulness to 

 mankind. We find that the Greek writer Plutarch, in his 

 less known works, the " Opera Moralia," writes a treatise 

 on the question whether land animals or water animals are 

 the cleverer. After this we seem to enter the dark ages 

 of natural history, in which Aristotle is practically our only 

 guide and writers on this subject are exceedingly scarce. In 

 the thirteenth century, however, Albertus Magnus, a Suabian, 

 described as the most learned man of his time, wrote some 

 books on animals. He appears to have been exceedingly 

 well acquainted with the works of Aristotle, and as his own 

 observations on natural history appear to be of little value, 

 it may be presumed that the better qualities of his works on 

 this subject are in great part due to the Greek philosopher. 

 He died in 1280, but his works were not published till over 

 three hundred years after his death. The very slow produc- 

 tion of natural history works continued for many years. In 

 the beginning of the sixteenth century Brunfels, of Bern, 

 published a history of plants with some figures. Some years 

 later Edward Wootton, a native of Oxford, published his 

 " De differentiis Animalium " at Paris in 1552. This work 

 again is described as more or less like a new edition of 

 Aristotle's writings on animals. 



But Wootton seems to have made some additions of his 

 own, and to have separated out some of the Aristotelian 

 chaff. We now arrive at Conrad Gesner, another very great 

 scholarwho published his" Historia Animalium, "in six books, 

 at Zurich between 1551 and 1587. This work appears to be 

 quite an encyclopaedia on animals, containing descriptions 

 of all those then known or mentioned by older writers, as well 

 as notices of the writings of previous authors. Caesalpinus, 

 a professor of Padua, issued a work called " De Plantis," at 

 Florence, in 1583, in which he uses the fruit for purposes of 

 classification of the 1500 plants known to him. 



In the last year of the sixteenth century Ulysses Aldro- 

 vandus published the first volumes of his work on natural 

 history, the later volumes being issued during the next few 

 years. This is another comprehensive work adorned with 

 many illustrations. Though its publication no doubt aided 

 in the diffusion of the knowledge of natural history, it did 

 not mark any very distinct advance in the progress of that 

 science. 



We have now arrived at the seventeenth century, when 

 Aristotle's reign in solitude was drawing to a close. Methods 

 of gaining knowledge with which Aristotle was totally un- 



