46 Introduction. 



points in which they vary ; but as throughout the entire order 

 there is so considerable a similarity of structure in this particular, 

 it will not be necessary for the due exposition of my subject to 

 enter into further details upon it. We have said enough to show 

 how worthy is the construction of their feet to give a name to 

 the whole order, as Insessores or ' Perchers.' 



In the Rasores, or ' Ground-birds,' we shall see a formation of 

 foot widely differing from both the above orders. These are a 

 harmless and quiet race, never preying upon other creatures, but 

 eating berries and grain, and such food as they can find upon 

 the ground; and they are subject to frequent attacks from 

 carnivorous birds as well as quadrupeds. Their flesh, too, being 

 very palatable, man is not the least of their destroyers ; but with 

 so many enemies from which to escape, their flight is laboured 

 and heavy, and they are unable to protract it to any great dis- 

 tance. Providence, however, which leaves no creature without 

 some means of defence, has provided for the ground-birds a 

 suitable remedy in their remarkable powers of running; for 

 this end such feet as those which I have shown to belong to the 

 above-named divisions would be little adapted ; in lieu of which 

 they have frequently but three toes, the hind one being 

 altogether omitted, or, if present, it is always very small and 

 considerably elevated. All the toes are very short, and excel- 

 lently adapted for running, not only for swiftness (though that 

 is often very great), but also for long continuance and protracted 

 exertion ; moreover, they are provided with limbs of great 

 muscular development, as well as with short and blunt claws : 

 thus the members of this order, when alarmed, run from the 

 supposed danger at their utmost speed, and endeavour to conceal 

 themselves under the thickest cover at hand; and it is only 

 when hard pressed, and other means of escape fail, that they rise 

 on the wing with considerable exertion, and fly heavily away. 



We come now to the two orders of Water-birds, and in each 

 of these we shall see the feet and legs adapted precisely to the 

 habits of their possessors. The Grallatores, or " Waders,' first 

 claim our notice. They seem to be a connecting link between 



