3i8 INSECTIVORES. 



in accordance with their purely terrestiial and non-fossorial habits. And the 

 broad first and second molar teeth of the upper jaw are characterised by having 

 five distinct cusps, of which the central one is very small, and connected with 

 the two inner ones by a pair of oblique ridges. 



The Hedgehogs. 



Genus Erinaceus. 



The European hedgehog, or urchiu, which is far the largest of the British 

 Insectivores, is the best known representative of a somewhat extensive genus 

 distributed over the greater portion of Europe, and parts of Africa and Asia, 

 although unknown in Madagascar, the Malayan Peninsula and Islands, Bumia, 

 Siam, Southern China, and Siam. 



The essential characteristics of the hedgehogs, as distinct from the gj'mnuras, 



are to be found in the dense coat of short spines covering the back and sides of 



the bod}-, and also the shortness of the tail. The hedgehogs have 36 teeth, of 



which, on each side, % are incisors, \ canines, and ^ cheek-teeth. An examination 



of the skull will show that the fir.st pair of front or incisor teeth in the upper jaw 



have remarkably long crowns, which are widely separated from one another in 



the middle line ; while the two remaining incisor teeth on each side of the same 



jaw are much smaller. It will farther be observed that the middle region of 



the palate of the skull contains some open spaces not occupied b3- bone. The 



common hedgehog {Erinaceiis europceus) is characterised by the short and almost 



imperceptible neck, the pig-like snout, from which it derives its popular name, 



and also by the shortness of its limbs. Exclusive of the short naked tail, 



which measures about \h inches, an average-sized hedgehog is about 10 inches 



in lengtli. The great peculiarity of all the hedgehogs is the power they passess 



of rolling themselves up into a ball-like form, presenting a chpravx-de-frise 



of spikes, impenetrable to the great majority of other animals. This rolling-up 



process is etFected by the aid of an extraordinary development of a layer of 



mu.scles found beneath the skin of most Mannnals, and known as the punlculus 



carnosus. When rolled up, the head and feet are tucked inwards, so that only the 



spines are exposed : and it requires a boM dog or fox to attack a hedgehog 



when in this condition. Under the microscope the spine is seen to be marked 



by a number of parallel longitudinal grooves ; the ridges between them being 



ornamented, in some of the foreign species, with rows of tubercles. Hedgehogs 



date from a remote antiquity : and it is doubtless solely due to this protective 



annour of spines that animals of .such low organisation and of such comparatively 



large size have been enabled to survive without resorting to the protection afforded 



by a subterranean or aquatic mode of life. 



The food of the European hedgehosc is very varied, including: 

 Habits. . .'. ., . 



insects, worms, slugs, snails, lizards, snakes, birds' eggs, rats, mice, and 



other small animals : while roots and fruit are also consumed to a certain extent. 



The partiality of hedgehogs for insects is often taken advantage of in ridding 



houses of beetles and cockroaches ; although the hedgehog itself not unfrequently 



