NOTICES OF NEW BOOKS. 437 
produce devastation among the bottom-living fishes of sea areas ; 
Cod, which are themselves the prey of Porpoises, devour great 
numbers of fish such as Herrings, and Crustacea such as Hermit- 
Crabs, &c.; Plaice and Flounders eat enormous numbers of 
Cockles, Mussels, and other small shellfish, and densely popu- 
lated beds of these molluscs are at times decimated by hordes of 
Starfishes ; pelagic fishes like Herrings and Mackerel feed to a 
creat extent on swarms of Copepods and other planktonic 
Crustacea, and twenty millions of Ceratium have been estimated 
in the stomach of a single Sardine.” Nature red in tooth and 
claw is proclaimed, and in no indefinite manner, by marine 
biological observations, and the survival of the fittest is as 
much a truth of the ocean as it is on land. Sometimes observed 
correspondences are very curious, as when it is maintained by 
fishermen that the operation of the Wild Birds Protection Acts 
has been to cause a diminution in the abundance of Cockles in 
some localities, since increased numbers of Gulls were spared to 
eat these molluscs. | 
We might continue quoting biological facts and conclusions 
from these pages, but this is beyond the province and the limita- 
tion of reviews in this Journal. It is rather our duty and 
pleasure to point out a volume on life in the sea which may well 
be added to the libraries of naturalists, and one which is in 
welcome contrast in authority and scientific value to many of the 
so-called Nature books which are now so frequently published. 

Through Southern Mexico; being an Account of the Travels of 
a Naturalist. By Hans Gapow, M.A., Ph.D., F.R.S. 
Witherby & Co. 
Wuen Dr. Gadow is found as author of a book of travel we 
know that we shall enjoy the writings of a naturalist, and that 
the Amphibia and Reptilia will certainly not be neglected; this 
anticipation is fully realized in the perusal of this well-illustrated 
yolume, and we accompany the writer from the tropical low- 
lands to the mountain regions of snow, thus gaining an insight 
of the environment of much Mexican animal life which we may 
have studied previously. 
We have, of course, a good account of the Axolotl, and 
