I44 The Naturalist in La Plata. 
in the mud; and this perhaps accounts for the more 
or less aquatic habits of the jaguar, aguara-guazu, 
the large Cervus paludosus, tapir, capybara, and 
peccary. Monkeys, which are most abundant, are 
a notable exception; but these animals have the 
habit of attending to each other’s skins, and spend 
a great deal of their time in picking off the parasites. 
But how do birds escape the ticks, since these 
parasites do not confine their attacks to any one 
class of animals, but attach themselves impartially 
to any living thing coming within reach of their 
hooks, from snake to man? My own observations 
bearing on this point refer less to the Ixodes than 
to the minute béte-rouge, which is excessively 
abundant in the Plata district, where it is known as 
bicho colorado, and in size and habits resembles the 
English Leptus autumnalis. It is so small that, 
notwithstanding its bright scarlet colour, it can only 
be discerned by bringing the eye close to it; and 
being, moreover, exceedingly active and abundant 
in all shady places in summer—making life a misery 
to careless human beings—it must be very much 
more dangerous to birds than the larger sedentary 
Ixodes. ‘The béte-rouge invariably lodges beneath 
the wings of birds, where the loose scanty plumage 
affords easy access to the skin. Domestic birds 
suffer a great deal from its persecutions, and their 
young, if allowed to run about in shady places, die 
of the irritation. Wild birds, however, seem to be 
very little troubled, and most of those I have exa- 
mined have been almos tentirely free: from parasites. 
Probably they are much more sensitive than the 
domestic birds, and able to feel and pick off the 
