214 THE RING OF NATURE 



and if a plant be burnt with care all the tiny girders 

 that kept it aloft remain, a system that no human 

 artificer could copy even to a scale ten times as 

 large. One of the effects of this construction, 

 though surely not a primary object as some books 

 suggest, is that browsing animals cannot eat 

 horse-tails. 



Now, the season of full luxuriance has gone by, 

 and the plants lie here and there across the line 

 of their growth. They are forming little banks 

 across the lake to catch the mud and debris which 

 the stream brings down. By such tactics these 

 ancient plants rapidly silt up the pond and 

 provide for their own extermination. For when 

 they have formed a given depth of soil in the 

 shallow water, their enemies the sedges and other 

 more terrestrial forms step in and snatch the 

 dominion. The horse -tail, like many another 

 pioneer, is ousted from the place, and, if it can 

 find such, goes forth into some other barren swamp 

 to teach pampered things how to grow there. 



Now that so many stalks have fallen the horse- 

 tail forest is no longer an impenetrable mystery. 

 I find, what in June I only suspected, that the 

 water-voles have their foraging ground within it. 

 They have been so secure all the summer and the 

 letting in of light has been so gradual that they 

 take little heed of our party on the bank. Even the 

 shrill cry of a child, ' There 's a vole,' does not in 

 the least agitate them. The object of the excited 

 remark sits calmly on the fallen branch his teeth 



