30 THE NATURAL HISTOET EEVIE^. 



twelfth edition the gigantic compilation of Gmelin showed the 

 world that Natural History, in its rapid progress, had already out- 

 grown the limits of any single book, and that thereafter the elabora- 

 tion of a general system of Nature, with descriptions of all the 

 species, was to be regarded as an impossibility. Blumenbach's 

 Manual is an example of an elementary systematic work, giving the 

 general outline of the Linnaean classification ; but within ten years 

 of the publication of G-melin's edition of the Systema NaturaB, 

 Cuvier commenced the work of innovation by the production of his 

 Tableau elementaire^ in which he indicated the division of the Animal 

 Kingdom into four groups, a system afterwards fully developed by 

 him in the two editions of his Regne Animale. 



In all these works, as also in Lamarck's Histoire Naturelle des 

 Animaux sass Vertebres, an effort was made to give the characters 

 not only of the larger groups, but of the genera, with descriptions of 

 illustrative species, and many of us can recollect a time when the works 

 of Cuvier and Lamarck formed the chief standards to which all newly 

 established generic groups were referred. That time, however, has 

 long since passed away, and from the rapid progress of Zoology during 

 the last thirty years, the number of genera has increased so greatly, 

 that, at the present day, any attempt to include short characters of 

 all the genera of animals within a single book of moderate compass, 

 is almost as impossible as it would have been for Cuvier and Latreille 

 to have described all the species known to them in the five volume^ 

 of their Btgne Animale. Many of our writers of Manuals have, accor- 

 dingly, abandoned the description of genera altogether, contenting 

 themselves with carrying their classification as low as the family 

 groups, and indicating, or briefly describing, typical examples of each 

 family. Others, again, and amongst them are the authors of the 

 Handbook now before us, have endeavoured to give a selection of 

 genera, a course of which we cannot altogether approve, — as, although 

 a certain number of types may, by this means, be ascertained by the 

 student, it is a question whether a much greater amount of usefulness 

 might not be attained by omitting these partial generic details, and by 

 devoting the space thus gained to the fuller elaboration of the structure 

 and life-history of the more prominent members of the larger groups. 

 Thus, in the work now under consideration, the generalities upon 

 the organisation, functions, &c., of the Classes and Orders are 

 reduced within the smallest compass, whilst some of the most im- 

 portant questions of modern Zoology, such as those relating to the 



