70 BRITISH MAMMALS 



are all small teeth of uniform size and appearance in the upper 

 jaw. Next to the supposed canine there is a minute premolar, 

 almost undistinguishable in the common shrew, but larger and 

 more evenly placed in other shrews. The second of the two 

 upper premolars — probably the fourth of the normal series — is 

 larger than the molars, as in the hedgehog. In the lower jaw 

 of the shrews there are only two incisor teeth on each side. 

 The first of these is a very long, procumbent tusk, markedly 

 serrated on its upper surface with two or three hook-like pro- 

 cesses. The second lower incisor is unimportant ; there is no 

 canine, and there is only one premolar. The teeth of the shrew 

 even more than those of the hedgehog suggest a very close 

 analogy of the way in which the specialised dentition of the 

 Rodents arose. 



In the shrews the ear conches are better developed than in the 

 moles or in the water shrew. The snout of the shrews is pro- 

 duced into a long, almost proboscis-like nose, from the sides of 

 which radiate a large number of vibrissse— those fine or coarse 

 bristles which are developed on the faces of so many mammals, 

 and which are the origin of the moustache in the human. The 

 skull of the shrew is strikingly different from that of other 

 Insectivores by the almost complete absence of the zygomatic 

 arch, or "cheek bone." 



Shrews do not burrow beneath the soil, but dart in and out 

 of the herbage, sometimes forming clearly marked runs round the 

 base of trees or round the stout stems of herbaceous plants. 



There are three pairs of mammas in the shrew. The breeding 

 season is apparently limited to the spring, at which time the 

 female gives birth to from five to seven young. 



Sorex vulgaris. The Common Shrew 

 This animal is about 2|- in. long from the snout to the base 

 of the tail, and the tail, which is tapering and covered with short 

 hair to the tip, is another i^ in. in length. The Common Shrew 

 is a reddish-gray in colour, the under parts being gray or pale 

 buff. Sometimes the fur is flecked with white. Exceptional 



