THE CLOTHING OF MAMMALS 



57 



shooting these spines at their enemies, and to a distance of several 

 feet ; but this is not so. When alarmed, old spines frequently 

 fall out, as the attempt is made to " bristle up " and look 

 dangerous, and hence the idea that they were forcibly ejected. 



The curious ant-eating pangolins of Africa have a yet more 

 remarkable covering, the body being encased in horny scales, 

 as may be seen in Fig. 17. These scales are really formed by 

 masses of hair cemented together, and between each scale a few 

 ordinary hairs are always to be found. But the pangolins are 

 not the only animals that have adopted cemented hairs as an 



FlG. 17. The African pangolin, wherein the hairy covering has been replaced 

 by overlapping scales. 



armature against attack, for the huge rhinoceros has developed 

 the same device, the great horns which surmount the snout 

 being similarly formed, as a section of a piece of the horn will 

 show when placed under the microscope. But while the scales 

 of the pangolin serve as a protective armour, the horn or horns 

 for some species have two horns of the rhinoceros are used 

 as weapons of offence. At any rate this is true of the two-horned 

 African species, but it is doubtful whether the Indian species 

 ever uses this weapon after this fashion. It seems, on the con- 

 trary, to trust to a pair of triangular and sharp-pointed tusks 

 lodged in the lower jaw. 



In some mammals the skin is largely replaced by bony plates, 



