JRI INTRODUCTION. 



the land, and the air, into one whole, and which, though 

 always perishing, are always being produced, offers a 

 field of contemplation which the longest life and the 

 most active mind cannot exhaust; and it has the advan- 

 tage over every other subject of study, as it presents 

 or awakens none of those bad passions and imperfections 

 which always present themselves when man and his 

 works are the objects of our inquiry. 



It has this farther advantage, that the details are 

 just as interesting as the whole ; that the subject which 

 is too small to be seen by the naked eye, is just as 

 perfect in all its parts, and as wonderful in the use of 

 them, as that which is of the most ample dimensions. 

 The little green moss that is as a pin's point upon a 

 wall or the bark of a tree, or the fungus that makes a 

 barely visible speck upon a leaf, is as perfect in its 

 structure, and as full of life as the pine or the oak that 

 rises majestically over the forest, and exhibits itself to 

 an entire county at once. The aphis, that hardly 

 crumples the rose leaf, or the animalcula, of which 

 myriads do not render a drop of water turbid, is equally 

 complete, and, in some respects, much more curious 

 than the horse or the elephant. Of the aphis, nine suc- 

 cessive generations, all females, succeed each other 

 every summer, and yet each produces a numerous 

 progeny ; and some of the animalculae increase in 

 number by a spontaneous division of the little bodies 

 of those previously existing. 



In order to understand any thing of the subject, we 

 must, indeed, study the small as well as the great, the 

 common as well as the rare. The rarest and the most 

 majestic of animals, cannot tell us more than the worm 



