VOICE AND PLUMAGE. 257 



victim. Eggs are peculiarly susceptible to the influence of electricity, and even when the 

 chick is partially matured, are often killed by a passing thunderstorm. In climates where 

 thunderstorms are so frequent and violent as in the lands which are inhabited by these 

 birds, it is needful that the eggs should be protected from the deadly influence, and we 

 accordingly find that the nests are oval or rounded in shape, and are made of substances 

 which are bad conductors of electricity. In accordance with this principle, Mr. Hill 

 proceeds to remark that " in tropical climate.s, there are a greater number of birds that 

 build close nests than in the temperate climates of Europe. In the West Indian Islands, 

 with the exception of the pigeon tribes and the Humming-birds (which latter build deep, 

 thick, cottony nests), the nests are almost uniformly circular coverings of dried grass, 

 varied by intermingled cotton, moss and feathers, with an opening from below, or an 

 entrance at the side. 



The Banana bird weaves a hammock of fibres, sometimes of horse-hair, deep and 

 purse-like, and loosely netted ; the Muscicapa olivacea (a fly-catcher), a hanging cot of 

 withered leaves, straw, moss, fibrous thread, and spiders' webs fitted together ; and the 

 mocking-bird builds in the midst of a mass of wicker-work a neat nest of straw lined 

 with hair. The woodpecker and the parrots take to hollow trees, but I hardly know any 

 arboreal beside which constructs any nest that is not wholly covered or domed over. 



Very many insects that are exposed to the air during tlieir metamorphoses weave 

 coverings of silk and cotton, in which they lie shrouded, at once impienetrable to moisture, 

 and uninfluenced by the disturbances of the atmosphere. It would seem that the object, 

 whatever it be, is the same in both. It is not for warmth that the insects spin these webs, 

 for they form their coverings of silk and cotton in the hottest period of the year ; and I 

 find that whilst all our birds that build open nests (the Humming-Birds build in May, 

 June, and later) breed early, those that construct the domed and spherical ones nestle in the 

 season between the sjiring and autumnal rains, when the air is saturated with electricity, 

 and is in a state of constant change." 



The semi-musical voice of the Vervain Humming-bird has already been mentioned. 

 With this exception, the Humming-birds seem to be without any melodious song, and 

 even in this case the song appears to be little more than a pleasing twitter, without 

 much melody, combination of notes, or musical force. Indeed, as a general rule, it is 

 found that the most brilliant songsters among the birds are attired in the plainest garb ; 

 and it may safely be predicted of any peculiarly gorgeous bird, that power, equality, and 

 sweetness of voice, are in invei'se ratio to its beauty of plumage. 



To this rule there are some exceptions, but these are more in appearance than in 

 reality. For example, the well-known blue-bii'd of America is very beautifid in plumage, 

 and yet possesses a song whose "low aeolian twitterings greet the morn." The canary- 

 bird again possesses, together with its brilliant voice, some degree of beauty in the 

 colouring of its plumage. But it must be remembered that the song of the Blue-bird 

 is, although sweet and pleasing, by no means remarkable for brilliancy of power, and that 

 the canary has little right to be ranked among the bright-plumaged birds, as a very great 

 proportion of the best songsters are of a dull olive green, hardly more showy than the 

 common linnet, and less so than the goldfinch or yellow-hammer. The goldfinch again 

 possesses a low sweet song, biit has very little vocal force, recpiiring to be crossed with the 

 canary before it attains any strength of voice. 



Eeference is, however, especially made to those birds whose plumage is of a peculiarly 

 resplendent cliaracter, absorbing, transmuting, and reproducing all the colours of whicli 

 we are cognizant, and almost dazzling the eyes of the spectator with their exceeding 

 splendour. Such plumage is to be found among the Humming-birds more than among 

 any other feathered creatures ; although there are examples of redrandant brilliancy of 

 attire in many other birds, such as the poe bird, the promerops, some of the sun-birds, and 

 our own common kiugfishei-. In all these creatures, the male possesses no real song, the 

 glorious beauty of the feathers compensating him and his mate for the absence of poetic 

 utterance. Why this should be the case is a problem ■^^'hich has long attracted the 

 attention of observant men, and it seems to me that a key may be found to its solution 

 2. s 



