192 NATURAL THEOLOaY. 



by water or macerated in the crop. Therefore, without a 

 grinding machine within its body, without the trituration of 

 the gizzard, a chicken would have starved upon a heap of 

 corn. Yet, why should a bill and a gizzard go together ? 

 "Why should a gizzard never be found where there are 

 teeth? 



Nor does the gizzard belong to birds as such. A gizzard 

 is not found in birds of prey ; theij- food requires not to be 

 ground down in a mill. The compensatory contriva:^ce 

 goes no further than the necessity. In both classes of birds, 

 however, the digestive organ within the body bears a strict 

 and mechanical relation to the external instruments for pro- 

 curing food. The soft membranous stomach accompanies a 

 hooked, notched beak ; short, muscular legs ; strong, sharp, 

 crooked talons : the cartilaginous stomach attends that con- 

 formation of bill and toes which restrains the bird to the 

 picking of seeds or the cropping of plants. 



III. But to proceed with our compensations. A very 

 numerous and comprehensive tribe of terrestrial animals are 

 entirely without feet ; yet locomotive, and in a very consid- 

 erable degree swift in their motion. How is the icant oj 

 feet compensated ? It is done by the disposition of the mus- 

 cles and fibres of the trunk. In consequence of the just col- 

 location and by means of the joint action of longitudmal 

 and annular fibres, that is to say, of strings and rings, the 

 body and train of reptiles are capable of being reciprocally 

 shortened and lengthened, drawn up and stretched out. The 

 result of this action is a progressive, and in some cases a 

 rapid movement of the whole body, in any direction to which 

 the will of the animal determines it. The meanest creature 

 is a collection of wonders. The play of the rings in an earih- 

 ivorm, as it craw^ls, the undulatory motion propagated along 

 the body, the beards or prickles with which the annuli are 

 armed, and which the animal can either shut up close to its 

 body, or let out to lay hold of the roughness of the surface 

 upon which it creeps, and the power arising from all these, 



