l6 SCIENCE OF THE GREEKS. pt. I. 



Great. Aristotle did much for astronomy, by collecting and 

 comparing the discoveries of the astronomers who came 

 before him. He is the first of the Greek writers who states 

 very decidedly that the earth must be a round globe, and 

 he discovered an eclipse, or occultation as it is termed by 

 astronomers, of the planet Mars by the moon. 



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 diff"erent parts of their body, and the man- 

 ner 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 animals, for if you cut a plant into pieces, each piece 

 will grow, showing that the parts of a plant are simple and 

 do not depend very closely upon each other. But an ani- 

 mal, and especially 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 se- 

 parated from the rest. These and many other very interest- 

 ing facts about animals are to be found in Aristotle's great 



