132 NATURAL HISTORY 



about five or six days old : they, I find, like puppies, 

 are born blind, and could not see when they came to 

 my hands. No doubt their spines are soft and flexible 

 at the time of their birth, or else the poor dam would 

 have but a bad time of it in the critical moment of par- 

 turition : but it is plain that they soon harden ; for 

 these little pigs had such stiff prickles on their backs 

 and sides as would easily have fetched blood, had they 

 not been handled with caution. Their spines are quite 

 white at this age; and they have little hanging ears, 

 which I do not remember to be discernible in the old 

 ones. They can, in part, at this age draw their skin 

 down over their faces; but are not able to contract 

 themselves into a ball, as they do, for the sake of 

 defence, when full grown. The reason, I suppose, is, 

 because the curious muscle that enables the creature 

 to roll itself up in a ball was not then arrived at its full 

 tone and firmness 2 . Hedgehogs make a deep and warm 



a The reason given in the text is probably the physical cause of the 

 fact observed by White. I have witnessed the same fact in the course 

 of this summer, in the young of a nest discovered in the Zoological 

 Society's Gardens in the Regent's Park. There were in it five young 

 ones, not two inches in length, and probably, at the time it was taken, 

 not more than two or three days old. The absence of the power of con- 

 tracting their skins gave to the little creatures a form very different from 

 that of the mother, who was taken at the same time with them. If the 

 similitude of the animal's form to that of the sea-hedgehog, indicated by 

 the name of the latter, be borne in mind, the shape of the parent would 

 have resembled, in its height as well as in its spiny covering, the edible 

 sea-egg, Echinus esculentus, LINN.; that of the younger ones would have 

 approached more nearly to the depressed sea-eggs of the genus Spatun- 

 gus, KLEIN, and the white short spines borne out on their otherwise 

 naked blue skin, were adapted to give greater force to the resemblance. 

 The body of the parent, elevated in the back and dropping rapidly down 

 on either side, presented a marked contrast with that of the young, 

 flattened above and spread out on the sides: the adult might be com- 

 pared to an egg; the young to the yolk of the same egg, deprived of the 

 support of the shell, but rather more extended lengthwise than across : 

 the shortness of the legs, in both cases, being such as scarcely to detract 

 from the similitude. The backward direction of the spines, in the young 

 animal, is well adapted to obviate an inconvenience hinted at by White 

 in a preceding passage. 



It is not perhaps altogether unworthy of remark that the whole of the 



