14 INTRODUCTION. 



very great ignorance and helplessness as regards even 

 the advancement of our own comfort as individuals. 

 Creation is so linked together as one whole, both in 

 space and in time, that we cannot know the nature and 

 learn the use of any one part without a knowledge of 

 the whole. For the want of this information, people 

 have often done very foolish things, such as wantonly 

 killing those rooks, that are of so much use in de- 

 stroying the larvae and eggs of insects, which, but for 

 rooks and other birds that feed upon insects, would 

 render the labour of the husbandman unavailing. In 

 like manner the garden spider is often destroyed, though 

 it be one of the grand preservers of the buds, the blos- 

 soms, and the fruit of the coming season. At the time 

 when these spiders become most abundant, the flies 

 are very numerous, most of the generations for the 

 passing summer having been produced ; and if all that 

 appear in the autumnal days were to live till they had 

 deposited their eggs, the different sorts of grubs and 

 caterpillars would be so abundant in the spring, that, 

 instead of fruit, hardly a green leaf would be left unde- 

 stroyed. 



One of the most valuable consequences of the study 

 of nature is, the removal of prejudices, under the in- 

 fluence of which we are apt to act very foolishly. In- 

 stead of looking at plants and animals as forming a part 

 of nature as one whole, we are apt to make our own 

 ignorance the rule of our action, and persecute one and 

 foster another, from dislike and regard founded on no- 

 thing but our own caprice. Thus, instead of being, as 

 we ought to be, the wise and skilful rulers of the world, 

 improving its beauty at the same time that we add to 



