H. G. BRONN 203 



Bronn's third factor in the production of variety of form 

 is adaptation to environment, or better, functional response 

 to environment. Bronn gives an excellent account of 

 adaptational modifications and calls attention, just as Milne- 

 Edwards did, to the numerous analogies of structure which 

 adaptation brings about. He works out the interesting view 

 that there is some connection between classificatory groups 

 and adaptational forms, especially such as are connected with 

 the function of locomotion : " Based upon a common 

 characteristic method of locomotion are whole or nearly 

 whole sub-phyla (Hexapoda), classes (mammals and reptiles, 

 birds, fishes, gastropods, pteropods, brachiopods, Bryozoa, 

 Rotifera, jelly-fish, polypes, sponges), sub-classes (mobile and 

 immobile lamellibranchs,echinoderms, walking and swimming 

 Crustacea, parasitic and free-living worms, and so on), often, 

 however, only orders and quite small groups (snakes, eels, 

 bats, sepias, medusae, etc.) " (p. 141). 



It was characteristic of the 'forties and 'fifties that trans- 

 cendental anatomy, along with Nature-philosophy, went 

 rather out of fashion, its false simplicities and premature 

 generalisations being overwhelmed by the flood of new 

 discoveries. A few stalwarts indeed upheld transcendental 

 views. We have already discussed the morphological system 

 built up by Richard Owen in the late 'forties, a system 

 transcendental in its main lines. We have seen the vertebral 

 theory of the skull still maintained in the 'fifties by such men 

 as Reichert and Kolliker, and we find J. V. Carus in I853 1 

 taking it as almost conclusively proved. 2 



We may mention, too, as showing clear marks of the 

 influence of transcendental ideas, L. Agassiz's work on the 

 principles of classification. 3 And Serres, who was Geoffrey's 



1 System der thierischen Morphologic, pp. 33, 457. Also C. Bruch, 

 Die Wirbellheorie des Schcidels, am Skelette des Lachses gepriift, 

 Frankfort-on-Main, 1862. 



2 In France the vertebral theory was advocated by Lavocat in his 

 Notivelle Ostcologie comparee de la tete des animau.v doinestiques, Toulouse, 

 1864. It seems also that Lacaze-Duthiers held fast to it even in 1872 

 Arch. zool. exp. gen., i., p. 51, 1872. 



3 An Essay on Classification, Boston, 1857, London, 1859. He 

 considered the classificatory categories to be the categories of the 

 Creator's thought, and hence natural, and in no sense mere conventions. 



