THE WEB OF LIFE 367 



A second point of importance is that very strong en- 

 couragement has rewarded many of the endeavours to 

 conserve life endeavours now happily on the increase. 

 Thus the three herds of bison maintained by the Govern- 

 ment of the United States comprised in 1910 over 150 head, 

 and the total of pure-bred bisons living in North America 

 was a little over 2,000 a satisfactory result of careful 

 protection. Equally full of promise are the records of 

 reserve-areas and bird-sanctuaries (like those of the Sel- 

 borne Society in Britain and the Audubon Society in the 

 United States), and of individual efforts (we think, for 

 instance, of Mr. Ford, the well-known motor-car manu- 

 facturer) to conserve what may be fairly called vital assets. 

 In Conclusion. These few instances must serve to illus- 

 trate the fact that animated Nature is a vast system of link- 

 ages and inter-relations. No creature lives or dies to itself. 

 The threads of one life get caught up and intertwined with 

 those of another. The liver-fluke of the sheep cannot get 

 on without the water-snail, nor the bitterling without the 

 freshwater mussel, nor the mussel without the minnow, 

 or some such fish, nor the clover without the bee. We find 

 these inter-relations in all degrees of perfection, some old 

 established and working smoothly, others in the making or 

 on trial, and others again apparently making for the ex- 

 tinction of one at least of the associates. But in whatever 

 stage of evolution they are, their interest is great, the 

 web of lif e is a great fact in Nature, and it is one of the 

 naturalist's delights and tasks to discern the threads. 



The general idea we have been expounding was tersely 

 put in an address by Dr. T. Muir. * The specialist must 

 aim a little more at width of outlook and knowledge of men 

 and affairs, must seek to moderate his exaggerated estimate 



