HUMEA-HUM MING-BIRD. 



789- 



torily. The leaflets of the Mimosa sensitiva collapse 

 when touched, but the entire leaves of the pudica 

 suddenly drop. 



HUME A (Smith). A very elegant plant intro- 

 duced into Europe from New South Wales. It is a 

 biennial, and belongs to the natural order Composifce. 

 It is not the flowers, but the elegantly pendent posi- 

 tion of its attenuated branches, which makes the 

 plant so much admired. 



HUMMING-BIRD (Trochiliu). A genus, or 

 according to some naturalists, a family of tenuirostral, 

 or slender-billed birds, having the feet anisoductylic, or 

 the two outer toes united at their base, and articulated 

 so as to form in some respects a kind of secondary 

 or supplemental foot, which holds on laterally against 

 t lie other two toes ; while these hold on against each 

 other. Thus the foot takes hold two ways ; and the 

 owner of it can run in almost any direction upon the 

 bolls and branches of trees. This is the foot of the 

 creepers which are so well known for the remarkable 

 manner in which they run up and down and round 

 and round the trees in our own forests. But the hum- 

 ming-birds, though they all have this description of 

 foot, have it in less perfection than the creepers, 

 because these feed mostly when using their feet, and 

 the humming-birds are in a great measure wing birds. 



They are a most singular genus or group, resem- 

 bling slightly the nectar suckers of the eastern con- 

 tinent, but still vastly different from them in almost 

 every respect ; and different indeed from all known 

 birds. They are the smallest of the feathered tribe, 

 some being not much more than half-an-inch in length ; 

 they are the most beautiful in the texture and colours 

 of their plumage ; for no matter and no other sub- 

 stance can come up to the richness of their tints, or 

 the glowing brilliancy of their metallic reflections. 

 They are the most active of all known birds, exceed- 

 ing in this respect even the swifts, they are still more 

 powerfully winged, in proportion to their size, than 

 these are ; and there are no birds which have the 

 sternum and the bones which give firmness to the 

 shoulder more finely developed. In fact, the whole 

 of their energy is concentrated upon this part of their 

 organization, and their different styles of flight are all 

 equally vigorous. Suspended in the air, and hovering 

 over a flower, their wings move with so much rapid- 

 ity that they are not seen, except as gleams of light 

 of different colours, but all radiant, as the beams of 

 the sun take them at those angles at which they give 

 out their different lustres ; and while the rapid motion 

 of the wings thus renders them invisible, except as 

 gleams of light playing around the little body of the 

 bird, they make a sound similar to that of the hum- 

 ming produced by the wings of bees and other 

 insects ; and it is on account of this, that they get 

 their English name of humming-birds. They can 

 hover about in this way for a considerable time ; and 

 this rapid motion of the wings, when hovering, appears 

 to give them an impetus for flight, in like manner as 

 a similar, though slower motion, gives an impetus to 

 eagles and other birds of prey, which stoop with 

 great rapidity through the air. In consequence of 

 the impetus thus given, the humming-birds can in an 

 instant dart from one place to another, upwards, 

 downwards, or laterally, without any apparent effort. 

 When they take longer flights, they do not fly on a 

 level with steady wing, but describe a series of flat 

 arches, each arch appearing as if it were a separate 

 leap iu the air. 



They are exclusively birds of the American con- 

 tinent, and in the rich and warm districts within the 

 tropics, they swarm as numerously as flies do in sum- 

 mer in the forests of Lapland or Canada. The known 

 species amount to several hundreds ; and as their 

 native localities are not easily explored, the unknown 

 species may be very numerous. Individually, they 

 absolutely swarm and people the whole atmosphere 

 with the most brilliant, though minute glories of the 

 living world, which are at the same time in a state 

 of wonderful activity ; they are not confined to 

 America, within the tropics, nor to the low and warm 

 parts of the tropical countries ; though every where 

 they are more numerous, and in greater variety, in 

 proportion as the place is more warm and fertile. 

 Some, however, are found high upon the table lands, 

 and slopes of the mountains, where the climate is not 

 only temperate, but absolutely cold ; others range as 

 far southward as the strait of Magellan, and pro- 

 bably, also, into Terra-del- Fuego, while others again 

 are found to the north of Canada, as high as the 

 fifty-seventh parallel of north latitude ; while on the 

 west side of North America they reach to latitudes 

 still higher. Nor must it be supposed, that even in 

 this cold latitude they are at all out of their place or 

 their element ; for when Captain King was surveying 

 the coast of the extreme south of America, he found 

 large flocks of humming-birds flying about, appa- 

 rently at their ease, in the middle of a snow storrn. 



The texture of their plumage is indeed as worthy of 

 attention as the tints of colour, and the brilliant 

 metallic reflections ; for though they are very little 

 birds in all the species, and not larger than humble- 

 bees in the most minute one, their plumage is exceed- 

 ingly compact, and probably forms a better defence 

 against alternations of heat and cold, and of drought 

 and moisture, than that of any other birds whatever. 

 The individual feathers arc beautifully formed ; and 

 more compactly laid than those of any others, if we 

 except the under parts especially, of those birds which 

 are almost constantly in the water without ever get- 

 ting wetted. But as it would greatly exceed our 

 limits to describe minutely, or even to enumerate, 

 half or even a tenth of the species, we must observe 

 some method in giving brief, general notices of those 

 parts of the structure which come most into action, 

 and may be considered as most characteristic of the 

 whole genus. 



The wings claim our first attention, as they are 

 most continually and most vigorously in use. Of the 

 birds in our own country they most nearly resemble 

 the wings of the swifts, but they are more curved than 

 these, and the birds can perform more evolutions on 

 the wing. The closed wings generally extend beyond" 

 the point of the tail, unless where that organ has pro- 

 duced feathers, which it has in some of the species. 

 The first quill is always the longest in the wing ; and 

 the other primary quills shorten gradually to the last 

 one. The secondary quills are generally speaking 

 very short ; and the* wings are not so much loaded 

 with coverts as they are in most birds. The strength 

 and stiffness of the wing are produced by the struc- 

 ture of the quills themselves. The shafts of these 

 are always very strong and elastic ; and in some 

 of the species the basal part of the shaft is so much 

 enlarged, that its diameter nearly equals the breadth 

 of the inner web. There is a sort of curvature in 

 the shaft, too, which, in the case of a violent strain 

 against the air, throws each quill partly under the one 



