﻿VOICE. 



165 



Hemiptera of Linnaeus, as some entomologists have lately 

 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 at most 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 their diminutive size, and the foliage 

 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 keep their 

 mates constantly informed of every fresh movement. We 

 particularly remarked this fact in a pair of bullfinches 

 which crossed our path in a shady lane this morning : 

 sometimes they were both 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. The 

 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, when 

 exploring with its mate the best spot for erecting their 

 new nest, or gathering materials for its construction. In 

 autumn, however, this latter bird is solitary, and it flits 

 across our path, or explores the tangled hedge, a silent 

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