VITAL PRINCIPLE. 15 



parts of the organized body, but with external objects, and 

 gives warning of the approach and retreat of salutary or 

 noxious particles. All its movements, however, are of a 

 passive nature. But the power which is now to be consi- 

 dered, though nearly related to irritability, is more varied 

 in its movements, as it excites us to act upon external ob- 

 jects. It is active, not passive. 



As organized bodies, when they begin to enjoy an inde- 

 pendent existence, require food for their support, we might 

 conceive it possible for a young plant or animal, by means 

 of the irritability of the vessels, and those determinate powers 

 which have been enumerated, to arrive at maturity, in the ab- 

 sence of counteracting agents, were the different substances 

 necessary for their nourishment, always placed in contact 

 with the vessels fitted for their reception. But the supply of 

 nourishment, even where most abundant, is situated at some 

 distance. Besides, during the whole term of life, obstacles 

 and dangers interrupt and destroy the exercise of the various 

 functions. From the form, size and vigour of the living 

 bodies which we see around us, we may therefore infer the 

 existence of a power which regulates the movements which 

 are necessary to obtain a supply of food, to remove or 

 counteract opposing obstacles, and to fly from impending 

 danger, or repair the injuries which it may occasion. This 

 active agent, which appears to be an inseparable com- 

 panion of organized existence, we venture to denominate 

 Instinct, and shall now endeavour to point out a few in- 

 stances of its operations. 



A. Regulates the Supply of Food. When the seed of a 

 plant is deposited in the soil, under circumstances favour- 

 able to its germination, the corcle expands, and, from the 

 nourishment furnished by the cotyledon, evolves the ra- 

 dicle and the stem. The former of these descends into 

 the earth, not according to the laws of gravitation, for it 



