82 



KNOWLEDGE. 



[May 1, 1893. 



sessing a pair of cbisel-like teeth in the front of the jaws, 

 and also have their molar teeth surmounted by a number 

 of small sharp cusps. 



The insectivorous moles include not only our common 



Fig. 1.— The Cape Golden Mole. 



mole (Talpa europaa), but also many other species belong- 

 ing to the same genus, as well as certain others which are 

 referred to distinct genera, all of which, for our present 

 purpose, may be collectively spoken of as true moles. Of 

 these, two genera (Tuljia and Scaptonyx) inhabit Europe 

 and Asia, while the other three are North American ; 

 Africa having no representatives of the group. It may be 

 well to mention that all the true moles have very broad 

 naked hands, each furnished with five toes carrying long 

 flattened nails, in addition to which there is a sickle-like 

 extra bone internally to the thumb. In burrowing, most 

 of them throw up the well-known molehills at certain 

 intervals from the tunnels driven in search of worms — 

 their chief food. 



In addition to these true moles. North America also 

 possesses certain other species known as shrew moles, 

 which, while belonging to the same family (Talpida:), are 

 distinguished by the absence of the sickle-hke bone in the 

 hand and the less expanded form of the bones of the upper 

 part of the fore-limb. They are thus clearly seen to be less 

 specialized creatures than our own mole, to which they 

 closely approximate in general appearance. 



Although belonging to the insectivorous order, the mole- 

 like creature represented in the foregoing figure indi- 

 cates a totally different family group. If we were to 

 examine the upper molar teeth of a common mole, we 

 should find that they had broad crowns, carrying cusps 

 arranged somewhat after the manner of the letter W. On 

 the other hand, in the Cape golden mole (as the animal 

 represented above is termed) the corresponding teeth have 

 triangular crowns carrying three cusps arranged in a V. 

 Moreover, if we look at the fore-hmb, we find instead of 

 the five-fingered hand of the mole that there are but four 

 digits, of which the lateral pair are small, while the two 

 middle ones are enlarged and furnished with triangular 

 claws of great power. As in the true moles, all external 

 traces of ears and eyes are concealed by the fur ; this 

 latter, it may be added, having a peculiar golden-gi-een 

 metallic lustre, from which the name of the animal is 

 derived. The golden moles, of which there are several 

 species, are much smaller than our English mole, and are 

 widely distributed in South Africa ; in which continent 

 they, in conjunction with the under-mentioned sand mole 

 and its allies, take the place occupied in the northern 

 hemisphere by the true moles. In tunnelling, the golden 

 moles come so close to the surface as to leave a ridge 



marking their course. The true moles and the golden 

 moles afford us, therefore, an instance of two entirely 

 distinct groups belonging to the same order having 

 assumed a perfectly similar mode of life, and, consequently, 

 having acquired a superficial general similarity in external 

 appearance. 



With the rodent moles, of which there is likewise more 

 than a single group, we come to animals of a totally 

 different order, which have assumed mole-like forms and 

 habits, and are popularly confounded with the true moles. 

 In common with the other membars of the order Roientia, 

 all these rodent moles are characterized by the presence 

 of a pair of powerful chisel-like incisor teeth in the front 

 of each jaw, while their molars have broad and flittened 

 crowns adapted for grinding. Moreover, instead of driving 

 their tunnels in search of worms, these rodent moles 

 burrow for roots and bulbs. All of them have very small 

 or rudimentary ears and eyes, large and powerful claws, 

 and short tails. 



One of the best known of these rodent moles is the great 

 mole-rat (Spalax), ranging from south-eastern Europe 

 to Persia and Egypt, in which the eyes are completely 

 covered with skin ; allied to which are the bamboo-rats 

 (tilikowi/s) of north-eastern Africa and Asia, distinguished 

 by having minute uncovered eyes and small naked ear- 

 conchs, and thus departing more widely from the mole 

 type. In the sandy soil of Egypt the mole-rat constructs 

 tunnels of great length in search of bulbs. In South Africa 

 these forms are replaced by the huge sand mole (Bathi/ciyus), 

 which attains a length of about ten inches ; and also by 

 certain smaller animals known as (Tcori/clius and Mi/nscalops, 

 which differ from tlie former by the absence of grooves in 

 their incisor teeth. This sand mole is commonly met 

 with in the flats near the shore, while the smaller forms 

 generally frequent land at a higher elevation. Sometimes, 

 however, both are found together, and the country is then 

 covered in all directions with hillocks precisely resembling 

 those made by our English mole. Although the sand mole 

 has uncovered eyes, these are not bigger than the heads of 

 large pins, and can have but little visual power. Still, 

 however, their presence serves to indicate that these 

 animals have not become so completely adapted to a sub- 

 terranean life as has the common mole ; and this is 

 confirmed by the fact that if their burrows are opened, the 

 sand moles after a few minutes usually protrude their noses 

 from the aperture with a view to discover the cause of the 

 disturbance, whereas an ordinary mole would under similar 

 circumstances remain below. 



Fio. 2. 



-The Long-clawed Mole-Vole. 



All the foregoing belong to one family of rodents ; but in 

 addition to these certain members of the Vole group (a 



