THE MODERN ZOOLOGICAL SYSTEM 299 



the new ones which were constantly being discovered. But the names 

 given were often complex and cumbersome and no uniformity existed 

 between the systems of terminology of different authors. Also the cus- 

 tom of giving two or more Latin names to a species was frequently in 

 vogue, but a binomial system, with the definite relation of the specific 

 to the generic name, was new. The genus, which gives the clue to the 

 natural affinities of the animal, was peculiarly Linngeus's invention. 



Attempts had also been made by Ray and Klein and other ad- 

 vanced thinkers to form a system which should express the natural re- 

 lationships of animals, but such attempts were generally not under- 

 stood or followed and most authors still employed unnatural methods 

 of arranging them. Many still followed Pliny and grouped animals 

 according to the environmental conditions surrounding them, placing 

 those together having similar methods of life, as land animals, fresh- 

 water animals, marine animals, flying animals, etc. Within each group 

 the species were often arranged in alphabetical order. 



Linnaeus's system was very quickly accepted by the scientific world 

 and went into universal use, and modern zoology may in a very real 

 sense be said to begin with the year 1758. 



So radical, however, was Linnasus's reform that neither the superi- 

 ority of his system nor the simplicity of his terminology would prob- 

 ably have been sufficient thus to procure its adoption if they had not 

 been proposed by a man of his great fame and commanding position in 

 the world. Linnaeus was considered by his contemporaries, because of 

 his numerous and important contributions^ to science and his eminence 

 as a teacher in the University of Upsala, as the greatest naturalist of 

 all time. His importance was indicated by the phrase in vogue : Deus 

 creavit; Linnaeus disposuit. 



The immediate acceptance of the Linngean classification had the 

 same effect upon the study of animals and plants in his day as that of 

 Darwin's theory of natural selection had almost exactly one hundred 

 years later. It gave a tremendous impetus to every branch of biolog- 

 ical investigation and started a new era. Systematic zoology, morphol- 

 ogy, physiology and experimental zoology all attracted able investiga- 

 tors who studied them with feverish activity. Comparative studies first 

 became possible, as now the facts of the science were for the first time 

 arranged in something like an orderly and natural manner, and the next 

 generation saw the rise of the sciences of comparative anatomy, paleon- 

 tology and comparative em.bryology, and also the first modern specula- 

 tions on the blood relationships and the evolution of living things. 



All these things gave a new importance to zoology and raised it 

 from the position it had occupied of a mere annex to medicine to the 

 dignity of an independent science. 



Linnaeus divided the animal kingdom into six -classes: Mammalia, 



