Friends and Foes 311 



scale insects, slugs, wireworm, grubs, and the various 

 other plagues known to the gardener and agriculturist 

 must also be passed over, and we must go on to 

 consider by what natural means these various creatures 

 are kept in check and prevented from becoming positive 

 enemies to all vegetation, instead of merely thinning 

 the ranks, to the advantage of the survivors. 



For, when one reads of flights of butterflies which 

 take days and weeks to pass, of armies of caterpillars 

 which stop the progress of railway trains, and of 

 dense clouds of locusts several miles long, it is quite 

 evident that unless their increase were restricted by 

 some very efficient means they would all more than 

 justify the locust's boast, and leave not so much as a 

 blade of grass. 



Man is utterly unable to cope with them by any 

 means at his present disposal, and when he interferes 

 with nature's way of keeping them within bounds, he 

 learns by hard experience his own utter helplessness, 

 and often not till then. 



In the Middle Ages people seem to have had the 

 feeling that they ought to be able to control grubs and 

 the like, by the mere word of command, and the 

 chroniclers of the time often give reports of the law- 

 suits instituted against these creatures. In 1479, for 

 example, the canton of Berne was troubled with such 

 an overwhelming plague of grubs that the Council 

 petitioned the Archbishop of Lausanne to banish them, 

 and the priests were authorized by him to do so. In 

 accordance with the usual custom on these occasions, 

 advocates were appointed for both parties — the grubs 

 and the people. A written summons was issued ; the 

 grubs were cited to appear, and some were brought 



