THE PROGRESS OF ZOOLOGY 473 



history of animals, the parts of animals, and the development of 

 animals. They reveal a remarkable familiarity with the facts of 

 comparative anatomy, physiology, and embryology. He was a 

 critical compiler, and, from the fabric of scattered facts and 

 fancies which existed at his time, produced a compact and 

 fairly accurate account of animals. 



Middle Ages. The Middle Ages are a blank, so far as zoo- 

 logical progress is concerned. Superstition was rampant, and 

 the belief in various fabled animals was prevalent. All zoo- 

 logical questions were referred to the ancient authorities, and 

 original investigation was at a standstill. In one controversy 

 a series of papers was published with respect to the number of 

 teeth in a horse's mouth. In this instance not one of the writers 

 seems to have thought of examining an animal, but all were 

 satisfied to quote the words of men who had died centuries 

 before. 



Linnaeus (1707-1778). After the intellectual awakening 

 of the sixteenth century, naturalists no longer tried to cover the 

 entire field of zoology, but restricted themselves to certain phases 

 of the subject. Thus the Swedish scientist, Linnaeus, chose 

 systematic zoology as a specialty and attempted to describe all 

 the existing species of animals and plants. He succeeded in 

 listing 4378 in the tenth edition of his greatest work, Sy sterna 

 NaturcB. His great influence, and the wide recognition which 

 was accorded his work, made the systematic side of zoology 

 the most active field of investigation for a long time after his 

 death. The aim of the systematic zoologist has been to describe 

 all the species of animals, and to arrange them according to a 

 natural system, i.e. a system that will show their true relation- 

 ships to one another. 



Cuvier (1769-1832). Systematic zoology led to careful 

 comparisons of the structures of one species of animal with 

 those of others, causing the development of the science of com- 

 parative anatomy. One of the greatest comparative anatomists 

 was the French scientist, Cuvier, who extended his studies over 



