690 



SHREW. 



SHREW (Sorex). A genus of mammalia be- 

 longing to the insectivorous family of Carnassiers, or 

 eaters of animal substances, in Cuvier's arrangement. 

 They are small animals of obscure and retiring habits, 

 and the number of the species, and the countries which 

 they inhabit, are not very clearly ascertained. They 

 are not, however, animals of very great importance ; 

 because, whatever may be their use in wild nature, 

 they do very little good and no harm to man. In so 

 far, however, as they have any bearing at all upon 

 human economy, they must be set down as the bene- 

 factors of man, which is true of all the insectivorous 

 mammalia, with the exception perhaps of those which 

 plough up the ground the mole, for instance ; and, 

 notwithstanding the disfigurement of the ground by 

 moles, the fact of their being injurious on the whole 

 is far from being fully established ; for, as the mole is 

 very voracious, and feeds in the earth, it is more than 

 probable that the small, animals upon which it lives 

 would, but for it, do far more mischief than it does. 

 The animals which the shrews most nearly resemble 

 arc those of the genus Mygale, called musk shrews, 

 but still they have sufficient distinguishing characters. 



In the case both of the genus alluded to and of 

 the shrews, some naturalists have been puzzled as to 

 the proper place they should hold in the system 

 that is, whether they ought to be classed with those 

 members of the rodentia which they resemble both 

 in their general form and in their habits, or with the 

 insectivorous Carnassiers. It must be admitted, that 

 the line of distinction between these is not always so 

 clear, as that one not very much skilled in natural 

 history can draw it the more so, that the animals 

 of both orders which thus approximate each other 

 are equally prone to eat animal matter. The dis- 

 tinction is, however, founded upon a character which, 

 when it is once known, is not easily mistaken or 

 misunderstood. The true character of the flesh- 

 eating animals is in the canine teeth, though the 

 strength of the mouth is thrown differently upon 

 them in the different races. The character of the Ro- 

 dentia, again, is in the incisors, and, whatever the charac- 

 ter of these may be, the rodent animal cuts as with pin- 

 cers, instead of inflicting punctured wounds like those 

 which are inflicted by the canines of the carnivora. 



The teeth of the shrews are generally thirty in 

 number, namely, twelve in the under jaw and eigh- 

 teen in the upper ; but they have sometimes two 

 less in the upper, which, of course, reduces the total 

 number to eight-and-twenty. In these teeth, how- 

 ever, the distinctions of the three kinds cannot always 

 be very clearly made out. That three of the cheek- 

 teeth in the back part of the jaw have the bristling 

 tubercles or points which are characteristic of all the 

 insectivorous Carnassiers, cannot be denied or over- 

 looked ; but it is not always easy or possible to 

 assign their proper functions to the teeth in the ante- 

 rior part of the jaws, so as to say decidedly which is 

 incisor, which canine, and which cheek-teeth. The 

 three tuberculous teeth, which are the only true cheek- 

 teeth, have before them five, or four, false molars in 

 the upper jaw ; and in the fore part of each jaw there 

 are two long and crooked teeth on each side, and 

 those in the upper jaw have a second branch or tuber- 

 cle at the base. The teeth of the shrews are thus 

 very different in their forms from those of the true 

 Carnivora, and yet they do not very much resemble those 

 of the Rodentia, for these have the long teeth at the 

 middle of the jaw and close to each other, whereas, 



in the shrews, the long teeth are apart with short 

 ones between them. The shrews are furnished with 

 a muzzle somewhat produced, though shorter than that 

 of the genus Mygale; and the form of the head is that 

 of a truncated cone, of which this muzzle forms the 

 vertex. The tongue is thick and conical, with fur- 

 rows on the surface, and corresponding furrows on 

 the palate; the organs of hearing are in general well 

 developed ; but most of the shrews can make them- 

 selves deaf when they please by means of membranes 

 which shut up the auricular openings. In this double 

 membrane of the external ear they have a consider- 

 able resemblance to the bats ; the eyes are similar to 

 those of the mole and other Carnassiers that live 

 under ground ; the optic nerve can hardly be traced, 

 and there are hardly any traceable nerves except 

 some branches of the fifth pair ; the usual muscles for 

 moving the eye are also hardly traceable ; arid the 

 ball of the eye is little else than a mere point ; in fact, 

 it appears that the shrews have very little dependence 

 upon this sense. This is one of the great points of 

 distinction between them and the rodent animals 

 with which they have sometimes been confounded. 

 Another character of the shrews is the odoriferous 

 glands which they possess. The odour given out 

 by these has some resemblance to that of musk, but 

 it is, generally speaking, offensive. The situation of 

 those glands is different from that of most, or all, of 

 the other mammalia that have them. In general they 

 are situated far backwards, but in the shrews they are 

 on the flanks, nearer the fore legs than the hind ones. 

 There are some peculiarities in the structure of these 

 glands, but they are of too technical a nature for 

 popular description. Indeed, the animals in them- 

 selves have so little interest, that the notice of them 

 is more a matter of curiosity than any thing else, and 

 yet they are so peculiar, and have resemblance to so 

 many races, that there is little doubt that if their 

 very obscure manners could be brought to light, they 

 have a very interesting tale to tell in the relation of 

 the mammalia. 



In their external appearance, and the colour and 

 covering of their bodies, the shrews have a consider- 

 able resemblance to some of the smaller members of 

 the rat family, and the popular name given to them 

 in many parts of the country is " shrew mice," under 

 which appellation the water shrew is not unfrequently 

 confounded with the water mole ; but a very little 

 attention suffices for distinguishing the one from the 

 other. The conical head, the produced snout, the 

 apparent smallness of the cerebral cavity, and the 

 imperfect formation of the eyes, at once point out 

 the shrews. The mammae of the females also disap- 

 pear, or at least can be found with difficulty, unless 

 at those times when they are wanted. 



In fact, we find in the shrews approximations to so 

 many animals, and at the same time so many cha- 

 racters which are peculiarly and exclusively their 

 own, that it is impossible not to regret the little that, 

 is known of them. In their eyes they have a very 

 considerable resemblance to the moles ; in their ears 

 there is an affinity to the bats ; and in the absorption 

 of the mammae, and also in the near approach or 

 absolute junction of the passages in the female, there 

 is some resemblance to the Monotremata. They are 

 also found in most parts of the world, with the ex- 

 ception of Australia, and they may be there ; and, in 

 all situations and climates, their habits, so far as 

 they are known, are very much the same. They 



