56 DARWINISM AND HUMAN LIFE 



are the agents in passing the plague-germs to 

 man. 



FAR-REACHING INFLUENCE OF CERTAIN ANIMALS : 

 EARTHWORMS. We realise the idea of the web 

 of life in another way when we consider the 

 far-reaching influence of particular kinds of acti- 

 vity, the best instance being the work of earth- 

 worms. In 1777 Gilbert White got at the very 

 root of the matter. " The most insignificant 

 insects and reptiles are of much more consequence 

 and have much more influence in the economy 

 of nature than the incurious are aware of. ... 

 Earthworms, though in appearance a small and 

 despicable link in the chain of nature, yet, if 

 lost, would make a lamentable chasm. . . . 

 Worms seem to be the great promoters of vege- 

 tation, which would proceed but lamely without 

 them, by boring, perforating, and loosening the 

 soil, and rendering it pervious to rains and the 

 fibres of plants ; by drawing straws and stalks 

 of leaves and twigs into it ; and, most of all, 

 by throwing up such infinite numbers of lumps 

 of earth called worm-casts, which, being their 

 excrement, is a fine manure for grain and grass. 

 Worms probably provide new soil for hills and 

 slopes where the rain washes the earth away ; and 

 they affect slopes probably to avoid being flooded. 

 . . . The earth without worms would soon become 

 cold, hard-bound, and void of fermentation, and 

 consequently sterile. . . . These hints we think 

 proper to throw out, in order to set the inquisitive 

 and discerning at work. A good monograph of 

 worms would afford much entertainment and 

 information at the same time, and would open a 

 large and new field in natural history." 



