672 ZOOLOaY SECT. 



retaining, as far as possible, the groups of Aristotle. His general 

 classification of animals is as follows : 



I. Animals with (red) blood [ Vertebrata]. 



1. Respiration pulmonary. 



A. Heart with two ventricles. 



(«) Viviparous. 



i. Aquatic [Cetacea]. 



ii. Terrestrial [other Mammalia]. 

 (Ji). Oviparous [Birds], 



B. Heart with one ventricle. 



Viviparous Quadrtipeds and Serpents,[i.e.,iie29<ito 

 and Amphibia]. 



2. Respiration branchial [Fishes]. 



II. Animals without (red) blood [Invertebrata]. 



1. Majora. 



A. MoUia [Cephalopoda]. 



B. Crustacea. 



C. Testacea [Gastropoda and Pelecypoda]. 



2. Minora. 



Insecta [Insecta, Arachnida, Myriapoda, and Vermes]. 



It will be noticed, that while the classification of Vertebrates is 

 fairly natural, being founded upon the rock of anatomy, the 

 arrangement of Invertebrates is no advance upon that of Aristotle : 

 the two main divisions depend upon mere size ; and Crustacea, 

 separated from the rest of the Arthropoda, are interposed between 

 Cephalopods and the remaining Mollusca. In association with 

 Ray must be mentioned his friend and fellow-worker Francis 

 Willughby, who made extensive contributions to Zoology. 



The eighteenth century saw the imperfect efforts of Ray 

 developed, and in some respects perfected, by Carl Linn^, or 

 Linneeus, universally recognised as the founder of modern 

 systematic Zoology — or more accurately Biology, since his reforms 

 equally affected Botany. Born in Sweden in 1707, two years 

 after Ray's death, he published the first edition of his 8i,stema 

 Naturae, in 1735, as a small pamphlet. The twelfth edition (1766- 

 68) was in three volumes, and was the last to receive the author's 

 corrections, but from materials left at his death in 1778 an 

 authoritative (thirteenth) edition in ten volumes was prepared by 

 J. F. Gmelin. 



It was Linnseus who first recognised the value of groups higher 

 than species — genera, orders, classes, &c., and employed them 

 in a definite and uniform way, with due subordination of one 

 to the other ; it was he who invented binomial nomenclature, 

 the advantage of which in promoting precision in systematic 

 work it is impossible to over-estimate. He gave each species 



