The Progress of Zoology. 247 



popular eyesight ; but it has yet to be proved that structure and 

 function are alone sufficient to afford satisfactory evidence of 

 relationship for the purpose of grouping the subjects of the 

 science into families and classes. There is a tendency in the 

 modern school cf zoologists to consider form as an accident of 

 life, and as very remotely connected with organization, whereas, 

 though it be very objective, it is certainly the true key to 

 structure and function. The botanists have the best of it in a 

 choice between two systems ; they are neither tied to Linnaeus 

 nor Jussieu : and while the system of the first is a mere aid to 

 memory, and as such invaluable, the other is self-expounding, 

 and conveys information in its very terms, yet becomes entirely 

 artificial under false pretences, when its assumed " natural" 

 principle fails in the application. 



It has never been attempted yet to establish a parallel 

 betweenBacon and Linnaeus, and show how the inductive method 

 so differently dealt with by each became the substantial basis 

 on which their successors in the several departments of physics 

 and natural history have built up the edifice of modern science. 

 The Novum Org anon and the 8 y sterna Natural are the two great 

 pillars which sustain the portico of the temple for the com- 

 pletion and embellishment of which so many energies have 

 been evoked, and so many splendid abilities combined. When 

 we compare the classification now generally adopted with 

 the scheme of the mammalia which Linnaeus so patiently 

 elaborated, we are astonished at the few departures from it 

 which have been found necessary in modern times. Cuvier 

 found ready to his hand a magnificent framework, and he did 

 well in boldly clothing it, to hold in reverence the genius of his 

 Swedish predecessor, who had determined the true elements of 

 zoology so accurately, and had invented a language so well 

 adapted to a comprehensive natural system, that the supply of 

 deficiencies was almost all that remained to be done. But the 

 deficiencies were many, and in none of the groups has recti- 

 fication been more necessary than in the section to which 

 Linnaeus assigned the opossums, in the order Ferce, placing 

 them between the bears, badgers, and racoons. Cuvier had the 

 advantage of knowing most of the marsupials of Australia, and 

 he arranged them in an order between the Carnassiers and 

 Rodents, making the one great peculiarity in their mode of re- 

 production, the basis of the order Marsupiata. This, as regards 

 the mammalia, was the distinguishing feature of Cuvier' s scheme, 

 and it is the one most likely soon to undergo a complete revolution. 

 It is in the classification of the tribes below the Mammalia, and 

 especially the invertebrates, that Cuvier shines ; as on the other 

 hand it was amongst those that Linnaeus lost himself, as witness 

 his class " Vermes," into which he flung all the animals that 



