212 The Naturalist in La Plata. 
distress from the prisoners reach and incite them 
to attempt their deliverance. Many social species 
are thus powerfully affected by cries of distress 
from one of their fellows; and some will attempt a 
rescue in the face of great danger—the weasel and 
the peccary for example. 
Mild and sociable as the vizcachas are towards 
each other, each one is exceedingly jealous of any 
intrusion into his particular burrow, and indeed 
always resents such a breach of discipline with the 
utmost fury. Several individuals may reside in the 
compartments of the same burrow; but beyond 
themselves not even their next-door neighbour is 
permitted to enter; their hospitality ends where it 
begins, at the entrance. It is difficult to compel a 
vizcacha to enter a burrow not his own; even when 
hotly pursued by dogs they often refuse to do so. 
When driven into one, the instant their enemies 
retire a little space they rush out of it, as if they 
thought the hiding-place but little less dangerous 
than the open plain. I have frequently seen viz- 
cachas, chased into the wrong burrows, summarily 
ejected by those inside: and sometimes they make 
their escape only after being well bitten for their 
offence. 
I have now stated the most interesting facts I 
have collected concerning the vizcacha: when others 
rewrite its history they doubtless will, according to 
the opportunities of observation they enjoy, be able 
to make some additions to it, but probably none of 
great consequence. I have observed this species 
in Patagonia and Buenos Ayres only; and as I have 
found that its habits are considerably modified by 
