DON FELIX D'AZARA. 67 



Carpenters, whilst others, on the contrary, rest only 

 on the tarsus. Some frequent fields, others woods, 

 and some both. These last appear in Paraguay in 

 the middle of winter; the others, only in spring; 

 and some are constantly resident, and during the 

 extreme cold conceal themselves in the thick woods. 

 It is said they make no nest, but lay their eggs on 

 the bare ground, whilst I am certain that some 

 bring forth their young on trees. They all so much 

 resemble each other, that after having seen one, you 

 can never be deceived as to the family to which they 

 belong ; and for the same reason, it is very difficult 

 to distinguish the different species. Nor is it easy 

 to discover the habits of nocturnal birds. The size, 

 on many occasions, is a great resource, but then 

 they must be very accurately measured ; the colour 

 of the plumage being of a very common kind, very 

 perplexed and confused, it can scarcely be expressed 

 in words. In short, the examination of these birds 

 is a work of great difficulty, and so very trouble- 

 some, that I have sometimes thrown them alto- 

 gether aside, to avoid the embarrassment of com- 

 paring and describing them." 



With one other extract, from his account of the 

 Small Martin, we fear we must dismiss his very 

 important ornithological labours. " I have often 

 observed this bird in the woods of Paraguay; it 

 there always flies above the highest trees ; and, if 

 in the plains, it sometimes approaches within thirty 

 or forty feet of the ground, it instantly remounts to 

 its accustomed elevation, so that I have never been 



