252 THE REASON WHY : 



&quot; Like birds, great nature s happy commoners, that haunt In 

 woods, in meads, and flow ry gardens, rifle the sweets, and 

 taste the choicest fruits, yet scorn to ask the lordly owner s 

 leave.&quot; HOWE. 



air, assiit the birds in finding their way to those other places where there it 

 food for them, 



&quot; At those places where the earth and the upper part of the forest are parched, 

 and the ardour of the unclouded sun continues to beat, there is a constant 

 rarefaction of the whole mass of the atmosphere ; and in consequence of this the 

 winds from the more humid surfaces must bloio towards those parched placet 

 with velocities proportional to the differences between the one and the other. 



&quot; When the forest which is the haunt of these birds becomes parched, their food 

 lessens, and they are compelled to be more on the wing in searcli after it. But on 

 which side soever there then happens to be a place more humid, and more 

 abounding in those creatures on which they feed, and which on this account is 

 better suited to them for the time, there is a wind which Hows from that side 

 towards the part ivhich is parched and heated ; and as the action of that wind 

 upon their flocculent feathers turns them round on their centres of gravity like 

 weather-cocks, their heads are, as they fly, turned to the wind, and against the 

 current. Their feathers thus assist than in finding out the direction of those 

 places where they can obtain food ; and though this is more remarkable in the case 

 of birds of Paradise than any other species, it is probable that many of the 

 softer-feathered birds are also assisted in their tropical migrations by tht 

 tet of the wind.&quot; 



Sub-order IV. Tenuirostres. 

 770. Why is the sub-order Tenuirostres so designated? 



From tenuis, long, and rostrum, a beak ; the birds comprehended 

 within it being characterise i by a long and slender bill. 



771. They are also by some classed as &quot; bee- eaters,&quot; or &quot;honey-suckers, the 

 great majority deriving their subsistence both from insects and the nectar of plants, 

 which they suck up by means of a long and filamentous tongue. The 

 representatives of this sub-order are the nuthatch, the creeper, the humming-bird, 

 the chough, and the hoopoe. They are clearly distinguishable from the sub-order 

 syndactyli by haying the toes separated from each other. 



772. Why is it essential that the bodies of humming-birds 

 should be motionless in the air? 



Because tj^e humming-bird seeks its food in the deep cups and 

 tubes which protect the seeds of various plants within the tropics. 



