I'M ELD AND FOREST. 7 I 



contents of the two volumes in question, we find that the wcrk, in 

 fact, is mostly devoted to the consideration of what the Germans 

 would call " binnenlandische Thiere," which is perfectly expressible 

 by the scarcely used English term "inland animals," with some refer- 

 ence to the distribution of marine animals, although extremely meagre. 

 Further, we find that even of the inland animals a very small propor- 

 tion are considered, and indeed only the vertebrates and a few inver- 

 tebrates are discussed. On a review of these discussions it becomes 

 also very soon apparent that the author had an autoptical acquaintance 

 only with the birds and several families of insects, and that his knowl- 

 edge of the other forms was almost entirely derived from a few authors 

 of more or less repute. Inasmuch as authors have greatly differed 

 in their estimation of the values of groups and their mode of weighing 

 differences in the several classes of the animal kingdom, we should 

 naturally expect that under such circumstances there would be consid- 

 erable incongruity in the basis of the work. Such, indeed, is the 

 case to a greater extent then even might at first be looked for in the 

 work of our author. 



Mr. Wallace discusses his subject under four leading heads. In 

 Part I. (vol. i. pp. 1-104) he treats of "the principles and general 

 phenomena of distribution ;" in Part II. (vol. i. pp. 105-170) of " the 

 distribulion of extinct animals;" in Part III. (vol. i. pp. 171-485, 

 vol. ii. pp. 1-164) he enters upon the consideration of "zoological 

 geography, a review of the chief forms of life in the several regions 

 and sub-regions, with the indications they afford of geographical 

 mutations;" and in part IV. (vol, ii, pp. 165-533) he gives, under the 

 caption of "geographical zoology, a systematic sketch of tlie chief 

 families of land [and fresh-water] animals in their geographical rela- 

 tions." We need only consider a tew of the questions involved. 



Mr. Wallace very properly postulates (vol. i. p. 83) that "a little 

 consideration will convince us that no enquiry into the causes and 

 laws which determine the geographical distribution of animals or 

 plants can lead to satisfactory results unless we have a tolerably accu- 

 rate knowledge of the affinities of the several species, genera, and 

 families to each other; in other words, we require a natural classifica- 

 tion to work upon." In order, too, to compare things and conditions, 

 it is necessary that they should be referred as nearly as possible to the 

 same common standard. In all these particulars we find a woeful 



