No. 457.] NOTES AND LITERATURE. 5I 
author to give more than a mere sketch. But in this short sketch is 
condensed a wealth of information that is of highest value for the 
student. Only a few words shall be said here to direct attention to 
the chief features of the book. 
The whole is divided in three main divisions: the first part, intro- 
duction, contains the discussion of general principles, part of which 
has been mentioned above. The two other parts are entitled : General 
Zoügeog: graphy, and Special Zoögeography. The former treats (in 9 
chapters) of the general laws of animal distribution, the relation of 
the range of animals to space, the means of dispersal and barriers to 
it, the struggle for space, the difference between centre of origin, areas 
occupied later on, and areas of survival. Further, the principal 
physical conditions of life and conditions of dispersal are discussed, 
and finally certain typical cases of distribution are selected as examples 
for the laws laid down. 
The last part, Special Zoögeography (17 chapters), contains first 
a short historical sketch of the work done previously in this line. 
Then follows a discussion of the schemes proposed for the division 
of the earth in zoógeographical unites, a discussion of the scheme 
accepted in this work (for continental life), and a sketch of the actual 
distribution of selected groups of animals (Mammals, Birds, Reptiles, 
Amphibians, Freshwater Fishes, Insects, Land Snails, Earthworms). 
The last chapter treats of marine life and the laws of distribution 
governing it. 
It is only to be regretted that the author did not have an oppor- 
tunity to more fully discuss certain points, and chiefly, to go into 
detail with regard to the geological development of the present 
condition of animal distribution: but lack of space explains this. 
Another exception might be taken with reference to the scheme 
accepted for the distribution of land animals: but since this point is 
to a degree a matter of personal taste with the author, we shall not 
discuss it here. A E 
Watchers of the Trails.'— Prof. C. D. G. Roberts’ latest collec- 
tion of animal stories, Ze Watchers of the Trails, does not fulfill the 
promise of his earlier Kindred of the Wild. lt suggests rather the 
endeavor to work up the poorer ore from a once rich vein. We can 
not be expected to follow the fortunes of a dragon-fly larva with the 
same interest that held us in the story of the bull-moose, the " King 
' Roberts, C. G. D. Ze Watchers of the Trails. Boston. L.C. — Co. 
1904. Svo, pp. 161. With many illustrations by Charles Livingstone Bull. 
