THE HEDGEHOG 



229 



with who have sufficient control of such 

 patches to wriggle their ears and move 

 their scalps. I fancy that these muscles 

 atrophy from disuse, as the power appears 

 to lessen with advancing years. 



something like the carapace of a tortoise, 

 with a decided thickening round its 

 lower edges. Beneath this skin-covering, 

 which, under such conditions, would seem 

 to be hardly attached to the body at all, 



Magnified section of pointed end 

 of quill, showing at the top the 

 pith, the inner, and outer shells ; and 

 generally the net-work of tissue in 

 the interior. 



2 and 2a. Magnified sections (super- 

 ficial) of quill, showing the mush- 

 room shape of the root end. and, 

 in 2a. a portion of the erecting 

 muscle attached to it. 



THE HEDGEHOG'S QUILLS. 



Magnified superficial view, showing 

 the exterior ribbing. 

 Cross sections, showing the pro- 

 jections of the inner shell into 

 the pith. 



Though the action by which the Hedge- 

 hog conv^erts himself into a ball of spikes 

 can be accomplished in a moment, the 

 muscles which determine it are highly 

 complicated — indeed, there can be few 

 muscles in his body which are not brought 

 into use when he rolls up. If a Hedge- 

 hog were to be, in imagination, divested 

 of his quills while in an ordinary stand- 

 ing position, there would appear on the 

 upper portion of his body and on his sides 

 a wrinkled grey skin-covering, in shape 



lies the sheet of pauuiculus caruosits^ 

 and there are connected to it, in addition, 

 a number of powerful muscles, which are 

 linked up to the head, tail, and limbs. 



On suspicion of danger, the first thing a 

 Hedgehog does is to wrinkle up his fore- 

 head so that his quills project outwards 

 and partially conceal his eyes. Perhaps 

 his most engaging expression occurs under 

 these conditions, for, as can be seen from 

 the illustrations, his eyes acquire an un- 

 due prominence when his hair and quills 



