1910.] De Blainville's Principles of Classification. 75 



In the meanwhile, the theory of the unity of organization, advocated by 

 Vieq d'Az\T and Geoffroy Saint-Hilaire, and destined to be developed into 

 fantastic extremes by Oken and his school, implied the existence of hidden 

 bonds of affinity between outwardly dissimilar animals, a problem which 

 had evidently engaged the attention of Linnaeus. The correlated principle 

 of analogous adaptations in different orders, was being slowly brought to 

 the foreground through the studies of Geoffroy Saint-Hilaire, Lamarck, 

 Frederic Cu-\aer, and de Blainville on the monotremes and marsupials, 

 although in the Cuvierian system these perplexing groups still remained 

 mingled with their placental analogues, and the whole problem of parallel- 

 ism was very imperfectly formulated (see pp. 52, 74). At this juncture Henri 

 Marie Ducrotay de Blainville, guided by his thorough studies of monotreme 

 and marsupial anatomy, and especially by his theory of the continuous 

 approach toward and divergence from ideal prototypes, evolved the re- 

 markable classification given in his 'Prodrome d'une nouvelle distribution 

 systematique du regne animal,' a classification which was perhaps the most 

 brilliant contribution in the entire history of the subject. 



De Blainville was not satisfied with superficial criteria, or with results 

 which recommended themselves either by their appeal to commonly accepted 

 standards or by reason of their mnemonic convenience. He drew his major 

 criteria of classification from the characters of the reproductive system and 

 of the skull, and although his scheme rested in part upon a theory stigmatized 

 as "metaphysical," it was nevertheless more seai'ching in its method and 

 more natural in its results than the Cuvierian system. Cuvier's classifi- 

 cation however had gained wide acceptance, because it was clear and 

 practicable and strong in its appeal to common sense. De Blainville's was 

 essentially esoteric, recondite, and repugnant to long accepted opinions and 

 usages and, moreover, as a product of "philosophical zoology," it encountered 

 the powerful and very effective opposition of Cuvier. Accordingly the merit 

 of de Blainville's tripartite division of the Mammals and the reasons for asso- 

 ciating in the same "ordre" such widely dissimilar groups as the Probos- 

 cidea and Sirenia (see below, p. 407) were but tardily perceived, and we find 

 Frederic Cuvier in his work of 1825 ('Des Dents des Mammiferes, con- 

 siderees comme Caracteres zoologiques') still arranging the orders of 

 mammals according to the number and superficial characters of the teeth. 



Coming to a nearer examination of de Blainville's classification we first 

 note that it seems permeated with the idea of adaptation and the resulting 

 obscurement of affinities. This is seen in the union of assemblages with the 

 normal limb-type of their order with other groups classed as "anomaux" 

 and extremely unlike them in external appearance but supposed neverthe- 

 less to represent the same "degree of organization." Thus the Cetacea are 



