148 
THE NATURALIST IN LA PLATA. 
July, 1892. 
and the changes witnessed during the last decade on the 
pampas exceed in magnitude those which had been previously 
effected by three centuries of occupation.” 
• The following extract relates to some of the fauna of this 
little-known and interesting district:—“The mammalia is 
poor in species, and with the single exception of the well- 
known vizcacha (Lagostomus trichodactylus), there is not one 
of which it can truly be said that it is in any special way the 
product of the pampas, or, in other words, that its instincts 
are better suited to the conditions of the pampas than to 
those of other districts. As a fact, this large rodent 
inhabits a vast extent of country, north, west, and south of 
the true pampas, but nowhere is he so thoroughly on his 
native heath as on the great grassy plain. There, to some 
extent, he even makes his own conditions, like the beaver. 
He lives in a small community of twenty or thirty members, 
n a vill age of deep-cliambered burrows, all with their pit- 
ike entrances closely grouped together; and as the village 
endures for ever, or for an indefinite time, the earth con¬ 
stantly being brought up forms a mound thirty or forty feet 
in diameter; and this protects the habitation from floods on 
low or level ground. Again, he is not swift of foot, and all 
rapacious beasts are his enemies; he also loves to feed on 
tender succulent herbs and grasses, to seek for which he 
would have to go far afield among the giant grass, where his 
watchful foes are lying in wait to seize him ; he saves him¬ 
self from this danger by making a clearing all round his 
abode, on which a smooth turf is formed ; and here the 
animals feed and have their evening pastimes in comparative 
security ; for when an enemy approaches, he is easily seen ; 
the note of alarm is sounded, and the whole company scuttles 
away to their refuge. In districts having a different soil and 
vegetation, as in Patagonia, the vizcacha’s curious, unique 
instincts are of no special advantage, which makes it seem 
probable that they have been formed on the pampas. 
“ How marvellous a thing it seems that the two species of 
mammalians—the beaver and the vizcacha—that most nearly 
simulate men’s intelligent actions in their social organizing 
instincts, and their habitations, which are made to endure, 
should belong to an order so low down as the Kodents ! And 
in the case of the latter species, it adds to the marvel when 
we*fmd that the vizcacha, according to Waterhouse, is the 
lowest of the order in its marsupial affinities. 
“ The vizcacha is the most common rodent on the pampas, 
and the Bodent order is represented by the largest number of 
species. The finest is the so-called Patagonian hare (Dolichotis 
patagonica ), a beautiful animal twice as large as a hare, with 
