VOICE. 
l65 
Hemipteraoi LinnjEUS, as some entomologists have ktely 
done, and this most beautiful and perfect analogy is al- 
together lost. 
(141.) Without attempting to assign causes for every 
thing we see in nature, it may safely be affirmed that 
one, at least, of the reasons why so much strength of 
voice has been given to the feathered creation, is, for 
the purpose of mutual recognition and companionship. 
Quadrupeds living upon the ground, when in quest of 
their mates, can discover them by sight, and by smell, for 
this latter faculty they enjoy in a much higher degree 
than birds — besides, they do not wander so far or so 
often from each other, and even then, being more or less 
exposed, they may be detected by the sight, or utmost by 
a slight exertion of the voice. But with birds the case 
is far different : they separate from their fellows at wider 
distances, and even when comparatively near they can- 
not recognise each other (at least those of the arboreal 
tribes) by reason of tlieir diminutive size, and the foliap 
of trees or plants. Hence it will be observed that the 
sexes of those species which habitually live together at all 
seasons, utter at intervals a peculiar sort of twitter when- 
ever they quit one tree for another, as if to licep their 
mates constantly informed of every iresh movement. We 
particularly remarked this fact in a pair of bullfinches 
which crossed our path in a shady lane this morning . 
sometimes they w’ere Iwth on the same side of the hedge, 
and sometimes opposite each other, never separating to a 
greater distance than fifteen or twenty yards: when 
nearer, this calling note was not heard, but so soon as 
one flew to another bush, in search of fresh food, it ap- 
prised its companion, who immediately followed. 1 ht 
same little signal notes are used by perching birds, 
which feed in societies, as the goldfinch and long-tailed 
titmouse, no less than by the wren in the spring, " 
exploring with its mate the best spot for erecting t leir 
new nest, or gathering materials for its construction, n 
autumn, however, this latter bird is solitary, am ' * * 
across our path, or explores the tangled hedge, a silent 
