828 MR.W. H. HUDSON ON THE [NoV. 19, 



as many eggs ; whilst, but for the Vizcachas, that ruin the grass and 

 occupy so much ground with their burrows, he could increase his 

 years's income by one or two hundreds of pounds sterling. That 

 the Vizcacha has comparatively no adverse conditions to war with 

 wherever man is settled is evident when we consider their very slow 

 rate of increase and yet see them in such incalculable numbers. The 

 female has but one litter in the year. She becomes pregnant late in 

 April, and brings forth in September ; the period of gestation is, I 

 think, rather less than five months. She has but two young ; this, 

 however, is not invariably the case, as I have opened one female con- 

 taining three, and therefore think it probable that they may some- 

 times have as many as four. 



The Vizcacha is about two years growing. A full-sized male 

 measures to the root of the tail 22 inches, and weighs from 14 to 15 

 pounds ; the female is 1 9 inches in length, and her greatest weight 

 9 pounds. Probably it is a long-lived, and certainly it is a very 

 hardy animal. Where it has any green substance to eat, it never 

 drinks water ; but after a long summer drought, when for months 

 they have subsisted on bits of dried thistle-stalks and old withered 

 grass, if a shower falls they will come forth from their burrows even 

 at noonday and drink eagerly from the pools. It has been errone- 

 ously stated that they subsist ou roots. Their food is grass and seeds ; 

 but they may also sometimes eat roots, as the ground is occasionally 

 seen scratched up about the burrows. In March, when the stalks 

 of the perennial cardoon or Castile thistle (Echinops ritro) are dry, 

 the Vizcachas fell them by gnawing about their roots, and afterwards 

 tear to pieces the great dry flower-heads to get the seeds imbedded 

 deeply in them, of which they seem very fond. Large patches 

 of thistle are often found served thus, the ground about them literally 

 white with the silvery bristles they have scattered. This cutting 

 down tall plants to get the seeds at the top, seems very like an act 

 of pure intelligence ; but the fact is, the Vizcachas cut down every 

 tall plant they can. I have seen whole acres of maize destroyed by 

 them, yet the plants cut down were left untouched. If posts be put 

 into the ground within range of their nightly rambles, they will 

 gnaw till they have felled them, unless of a wood hard enough to 

 resist their chisel-like incisors. 



The strongest instinct of this animal is to clear the ground 

 thoroughly about its burrows ; and it is this destructive habit that 

 makes it necessary for cultivators of the soil to destroy all the Viz- 

 cachas in or near their fields. On the uninhabited pampas, where 

 the long grasses grow, I have often admired the vizcachera ; for it is 

 there the centre of a clean space, often of half an acre in extent, on 

 which there is an even close-shaven turf: this clearing is surrounded 

 by the usual rough growth of herbs and giant grasses. In such 

 situations this habit of clearing the ground is eminently advantage- 

 ous to them, as it affords them a comparatively safe spot to feed and 

 disport themselves on, and over which they can fly to their burrows 

 without meeting any obstruction, on the slightest alarm. 



Of course the instinct continues to operate where it is no longer 



