28 THE AMERICAN MUSEUM JO URNAL 



order in teeth and skull, but we know practicallv nothing of when or 

 how the great wing-membranes were developed, except that thev 

 must have been of very ancient origin, for in the Oligocene epoch this 

 feature was as fully formed as now. A few fragmentary jaws and 

 wing bones are shown in the collection. 



III. INSECTIVORA. 



Hedgehogs, Moles, Shrews etc. Table-case. 



Small mammals of rather inferior organization with claws on the 

 toes five digits on each foot, simple teeth with sharp cusps on the 

 crowns and no gnawing teeth. 



The Insectivora are an order of animals defeated and dis- 

 appearing in the struggle for existence, owing to the superior 



FIG. 21. SKULL OF THE HEDGEHOG. 

 A surviving type of the insectivor.i. Natural size 



intelligence or better adaptation of their competitors. To escape 

 utter destruction they have been forced into one or another 

 peculiar mode of existence or method of defense, or have been 

 driven to take refuge in the remoter comers of continents or in 

 oceanic islands, where competition is less severe. The Hedge- 

 hogs have survived by virtue of their stout and efficient prickly 

 coat, which deters almost any carnivorous animal from meddling 

 with them. The IMoles have taken refuge in the earth, where 

 their rivals are few^ and they are out of reach of most enemies. 

 The Shrews are partly protected by their unpleasant odor, partly 

 by their small size, nocturnal habits and burrowing or otherwise 



