1872.] HABITS OF THE VIZCACHA. 829 



of any advantage. In summer, when the thistles are green, even 

 when growing near the burrows, and the giant thistle (Carduiis 

 mariana) springs up most luxuriantly right on the mound, the Viz- 

 cachas will not touch them, either disliking the strong astringent sap 

 or repelled by the thorns with which they are armed. As soon as they 

 dry, and the thorns become brittle, they are levelled ; and afterwards, 

 wben the animal begins to drag them about and cut them up, as hia 

 custom is, he accidentally discovers and feasts on the seed. For 

 Vizcachas are fond of exercising their teeth on hard substances, 

 such as sticks and bones, just as cats are of "sharpening their claws" 

 on trees. 



Another remarkable habit of the Vizcacha, that of dragging to 

 and heaping about the mouth of his burrow every stalk he cuts 

 down, and every portable object that by dint of great strength he 

 can carry, has been mentioned by Azara, Darwin, and others. On 

 the level plains it is a useful habit ; for as the Vizcachas are con- 

 tinually deepening and widening their burrows, the earth thrown out 

 soon covers up these materials, and so assists in raising the mound. 

 On the Buenos-Ayrean pampas numbers of vizcacheras would an- 

 nually be destroyed by water in the great sudden rainfalls were the 

 mounds less high. But this is only an advantage when the ani- 

 mals inhabit a perfectly level country subject to flooding rains; 

 for where the surface is unequal they invariably prefer high to low 

 ground to burrow on, and are thus secured from destruction by water; 

 yet the instinct is as strong in such situations as on the level plains. 

 The most that can be said of a habit apparently so obscure in its 

 origin and uses is, that it appears to be part of that instinct (to which 

 so little attention has been paid) of clearing the ground about the 

 village. Every tall stalk the Vizcacha cuts down, every portable 

 object he finds, must be removed to make the surface clean and 

 smooth ; but while encumbered with it he does not proceed further 

 from his burrows, but invariably retires towards them, and so deposits 

 it upon the mound. So well known is this habit, that whatever 

 article is lost by night — whip, pistol, or knife — the loser next morn- 

 ing visits the vizcacheras in the vicinity, quite sure of finding it 

 there. People also visit the vizcacheras to pick up sticks for fire- 

 wood. 



The Vizcachas are cleanly in their habits ; and the fur, though it 

 has a stroug earthy smell, is kept exceedingly neat *. They have 



* Have none of the great anatomists ever made a special study of the Vizca- 

 cha? The hind leg and foot afford a very beautiful instance of adaptation. 

 Propped by the hard curved tail, they sit up erect and as firmly on the long 

 horny disks on the undersides of the hind legs as a man stands on his feet. 

 Most to be admired, on the middle toe the skin thickens into a round cushion, 

 in which the curved teeth-like bristles are set ; nicely graduated in length, so 

 that " each particular hair '' may come into contact with the skin when the animal 

 scratches or combs itself. As to the uses of this appendage there can be no dif- 

 ference of opinion, as there is about the serrated claw in birds. It is quite ob- 

 vious that the animal cannot scratch himself with his hind paw (as all mammals 

 do) without making use of this natural comb. Then the entire foot is modi- 

 fied, so that this comb shall be well protected and yet not be hindered from 

 performing its office : thus the inner toe is pressed close to the middle one, and 



