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increase. For the Author of Nature intended, that 

 vegetables which have slender stalks and erect leaves 

 should be copious and thick set, and thus afford food 

 for so vast a quantity of grazing animals. But what 

 increases our wonder is, that although grass is the 

 principal food of such animals, yet they touch not 

 the flower and seed bearing stems, that so the seeds 

 may ripen and be sown. 



The caterpillar of the moth, which feeds upon 

 grass to the destruction thereof, seems to bs formed 

 in order to keep a due proportion between this and 

 other plants. For grass when left to grow freely, 

 increases to that degree as to exclude all other plants 

 which would consequently be extirpated, unless the 

 insect sometimes prepared a place for them. And 

 hence it is, that more species of plants appear, when 

 this caterpillar has lain waste the pasture the preced- 

 ing year, than at any other time. 



But all plants sooner or later must submit to 

 death. They spring up, they grow, they flourish, 

 they bear fruit, and having finished their course, re- 

 turn to the dust again. Almost all the black mould 

 which covers the earth is owing to dead vegetables. 

 Indeed after the leaves and stems are gone, the roots 

 of plants remain ; but these too.at last rot and change 

 into mould. And the earth thus prepared restores to 

 plants what it has received from them. For when 

 seeds are committed to the earth, they draw and ac- 

 commodate to their own nature the more subtle parts 

 of this mould ; so that the tallest tree is in reality 

 nothing but mould wonderfully compounded with air 

 and water. And from these plants, when they die, 

 just the same kind of mould is formed as gave them 

 birth. By this means fertility remains continually 

 uninterrupted { whereas the earth could not make 

 good its annual consumption, were it not constantly 

 recruited. 



In many cases, the crustaceous liverworts are the 

 first foundation of vegetation. Therefore, however 

 despised, they are of the utmost consequence in the 



