78 THE ZOOLOGIST. 



compare the young of these two snakes we find them to be 

 absolutely identical in their markings, and, in the absence of 

 any structural differences, we are forced to conclude that they 

 only represent two forms of the same species, of which the 

 latter is the more primitive." Again, colour and markings are 

 frequently, perhaps too frequently, employed in theoretical con- 

 clusions and suggestions. Such an instance is found in the eye- 

 spot on the hood of the Indian Cobra. But, as Dr. Boulenger 

 observes, " at present it is as inexplicable as the lugubrious 

 emblem on the thorax of the Death's-head Moth. It cannot 

 be suggested that it is a warning mark intended to terrify 

 intruders, for when the Cobra is at rest the hood is folded, and 

 the characteristic marking is not displayed ; whilst, as soon as 

 it is aroused and the hood expanded, it faces its enemy in such 

 a way that the spectacle, or ocellus, is not to be seen." Again, 

 as regards the now excessive advocacy of "mimicry"; among 

 Snakes "there are equally striking instances of what one would 

 regard as mimics if they only occurred together ; thus, there is 

 no better case of general resemblance between a poisonous and 

 a harmless Snake than we find in the Indian Cobra and the 

 Coluber corais of Tropical America, where Cobras are absent, or 

 between a Viper and the Boid Engyrus asper, from New Guinea, 

 where no Vipers exist." 



But we must quit these delightful realms of philosophical 

 zoology or a wrong impression may be given of the book. It is 

 practical to the last degree, and the naturalist and student will 

 find, by description and illustration, what he requires to aid him 

 in the identification and knowledge of European Snakes, the 

 British species being thus included. There is a good and 

 useful bibliography, as well as distributional lists to readily 

 enable the student to follow the range of species in the different 

 parts of Europe. 



The Life of the Mollusca. By B. B. Woodward, F.L.S., &c. 

 Methuen & Co., Limited. 



In this book Mr. Woodward has had the somewhat difficult 

 task of combining a description of the well-known outer cover- 

 ings or shells with that of the living animals within them. Both 



