16 SCIENCE OF THE GREEKS. PT. I. 



But the best scientific work of Aristotle was his study of 

 animals. He persuaded Alexander the Great, who governed 

 Greece at that time, to employ several thousand people to 

 collect specimens of animals in all parts of Europe and Asia, 

 and to send them to Athens. Here Aristotle examined 

 them and arranged them under different classes according 

 to their organs, or different parts of their body, and the 

 manner in which they used them. Many of Aristotle's 

 divisions of the animal kingdom are still in use, and he may 

 fairly be called the Founder of Zoology. He pointed out 

 that we can trace an unbroken chain from the lowest plant 

 up to the highest animal, each group being only divided 

 from the next by very slight differences ; nor can we tell, he 

 said, where plants end and animals begin, for there are some 

 forms which are so like both plants and animals that we 

 cannot decide in which division to place them. 



He also pointed out that the life in plants is much 

 lower than in most animals ; for if you cut a plant into 

 pieces, the separate pieces will often grow, showing that 

 the parts of a plant are simple and do not depend very 

 closely upon each other. But any one of the higher 

 animals is a most complicated piece of machinery. If you 

 hurt or destroy any of the most important parts the whole 

 body dies, and if you cut off any part whatever, that part 

 dies as soon as it is separated from the rest. These and 

 many other interesting facts about animals are to be found 

 in Aristotle's great work on Natural History, which, how- 

 ever, you must remember, was only one out of many philo- 

 sophical works written by him. 



Theophrastus, 371 B.C. Among the pupils of Aristotle 

 was a man named Theophrastus, who was born at Eresus, 

 371 B.C. Theophrastus devoted himself chiefly to the 

 study of plants, and is the first botanist whose name has 



