578 SCIENCE PROGRESS 



The Wanderings of Animals. By Hans Gadow, F.R.S. Cambridge Manuals 

 of Science and Literature. [Pp. vi + 150.] (Cambridge : University Press, 

 1913. Price is. net.) 



Dr. Gadow's little volume of 150 pages with 17 outline maps is a marvel of 

 comprehensive lucidity, and in many respects the best book on the geographical 

 distribution of animals that has been written. He begins with a just and lively 

 account of the history of his subject from Bufifon to the latest treatise, and from 

 his criticism of his predecessors leads us gently to his own point of view. The 

 attempt to divide the world into zoological regions of general application is doomed 

 to failure ; even with regard to single groups such as birds, beasts, or fishes, there 

 is the trouble that the regions must have been different at different geological 

 epochs. Study of geographical distribution is nothing less than " the history of 

 life in time and space." The fossil history of each group must be studied and an 

 idea obtained as to the geographical configuration of land and water at the time 

 of its appearance, and throughout its subsequent history. Pan passu there must 

 be an investigation of animals with regard to their environment, because the 

 power of taking advantage of land connections or other possible avenues of 

 dispersal is limited by the presence of suitable conditions for the radiating 

 animals. 



In his second chapter Dr. Gadow discusses the effect of the environment in 

 moulding the fauna and flora of any locality, selecting forests, deserts, and 

 high mountains as extreme examples. He states briefly the characteristic facies 

 of each of these regions and comments on the possibility of making the difficult 

 discrimination between convergence and blood relationship. In a short chapter 

 on " Spreading" he points out that the many forms with an almost world-wide, 

 continuous distribution must be supposed to have spread from a common centre, 

 and in simple language he enunciates the bearing of limited food-supply and 

 progressive increase in numbers due to reproduction. After discussing the 

 density of the existing fauna, he proceeds to give a short summary of what he 

 conceives to have been the leading features of terrestrial geography from Permian 

 to recent geological ages, and illustrates his views with an ingenious set of 

 diagrams. Obviously he is on controversial ground here, but although every one 

 will not agree with all the details he suggests, no one can dispute the almost 

 incredible amount of information that he has contrived to pack into a short 

 chapter. 



The second half of his volume is occupied by an account of the distribution of 

 various selected groups — Earthworms, Fresh-water Crabs and Crayfishes, Fish, 

 Amphibians, Reptiles, Birds, and Mammals. His object appears to have been an 

 explanation of the principles by which the subject must be elucidated rather than 

 a detailed statement of the facts. 



We regard the book as quite admirable ; experts will rejoice in the freshness 

 and interest of the exposition, and the novice will acquire from it much knowledge 

 and a wide grasp of how to gain more. 



Penal Philosophy. By Gabriel Tarde. English Translation by Rapelje 

 Howell. [Pp. xxxii + 581.] (London : W. Heinemann, 1912. Price 20^.) 



THE late Prof. Tarde's well-known work, Philosophie penale, appeared first in 

 1890, and had reached a fourth edition in 1903. The version now before us was 

 undertaken, and has been very ably made, by the translator, and those who hav e 



