NATURAL HISTORY. 11 



Ye chief, for whom the whole creation smiles ; 

 At once the head, the heart, the tongue of all, 

 Crown the great hymn ! " THOMSON. 



trith it ; while the view of that which they attempted to seize would 

 be obstructed by the nose and cheeks. 



15. Why is a horizontal posture unfitted for the human body ? 



Because if man were to attempt such a posture he would b 

 compelled to rest on his knees, with his thighs bent towards tha 

 trunk ; an attempt to advance them would be painful, and with 

 his legs and feet would be inmioveable and useless. Or, he must 

 elevate his trunk on the extremities of his toes, throwing his head 

 downwards, and exerting himself very forcibly at every attempt to 

 bring forward the thighs by a rotary motion at the hip-joinfc. In 

 either case, the only useful joint would be that at the hip, and the 

 legs would be scarcely superior to wooden or rigid supports. 



16. WJiy is tlie variation of animal bodies most common in 

 the centre, whilst towards the extremities there is comparative 

 uniformity ? 



Because the central parts, as 'the skull, spine, and ribs, are in 

 their offices permanent ; whilst the extremities, as the hands and 

 feet, are adapted to every exterior circumstance. In all animals 

 the office of the cranial part of the skull is to protect the brain, 

 that of the spine to contain the spinal marrow, and that of the ribs 

 to perform the part of respiration. It is unnecessary, therefore, for 

 these parts to vary in shape, while their offices remain the same. 

 But the shoulder, on the contrary, must vary in form, as it does in 

 motion, in different animals ; so must the shape of the bones and 

 of the joints more distant from the centre be adapted to their va- 

 rious actions, and the wrist, the ankle, and the bones of the fingers 

 and toes must change more than all the rest, to accommodate the 

 extremities to their diversified offices. 



17. Why cannot a statue stand upright on its feet without support, 

 although it may be a model of symmetry in all its parts, and is placed 

 in that attitude which is the most adapted to man ? 



Because a statue has but one centre of gravity, and when that 



