94 Natural Theology. 



is for man and not for himself that the work is 

 done. 



There is in all animals an organic or vegetable 

 life, which they have in common with the plants. 

 In the lowest forms of animal life we can hardly 

 recognise anything higher than this organic and 

 functional action. There is certainly but the mere 

 glimmering of instinct needed, because in the lowest 

 types structure and function can complete the adap- 

 tation of the animal to the world without the inter- 

 vention of volition. What needs the oyster more 

 than the plant ? So far as we can judge, it has no 

 more conscious relation to its young than the tree 

 has to its seed. The production of its young is 

 simply the result of organic change, the law of its 

 growth, like the budding and blossoming of the tree. 

 The movement of the shell seems to be voluntary. 

 Certain it is that volition is reduced to its minimum, 

 and consequently instinct, since instinct is always 

 connected with volition. We must, then, in animals 

 of such low type, recognise mainly adaptation of 

 structure and function. But, one step higher in this 

 division of animals, we see marked cases of the rela- 

 tion of instinct to specific structure the absolute 

 necessity of the combination of the two to secure 

 the well-being of the animal. The Natica, a shell- 

 fish found on our coast, can hunt his prey in the 

 sand. He feeds upon other shell-fish, sometimes 

 upon his own kind. He is armed with a long, rasp- 

 like tongue, and instinct teaches him to use it, in 

 piercing the shell that is closed in vain against 



