BIRDS. 
CHAPTER I. 
General Characteristics,— Glass Aves. 
A TRAVELLER may in many parts of the world journey from one week’s end to 
another without coming across a single Mammal or Reptile,. but few indeed are the 
regions where bird-life, in some form, will not present itself more or less abundantly 
to his gaze; and in no country is this exuberance of bird-life, as contrasted 
with the apparent scarcity of Mammals and Reptiles, more remarkable than in the 
British Islands. This abundance is largely due to the great majority of Birds 
being diurnal in their habits, whereas most Mammals are nocturnal, but it is 
chiefly owing to the Birds being more numerous in most parts of the world, both 
as regards individuals and species. On this account alone Birds have always 
aroused a widespread interest even among those who pay no particular attention 
to Natural History; and in addition to it we have the beauty of their form, the 
gorgeous hues with which their plumage is so frequently adorned, and the power 
of melodious song with which so many members of the class are endowed. Then, 
again, the many interesting points connected with their habits, and more especially 
their conjugal affection and the care they bestow on their helpless young, have, 
combined to aid in producing the universal enthusiasm for what have been most 
vol. hi.—19 
