14 HABITS OF WOEMS. Chap. I. 



individuals, which are generally affected by 

 the parasitic larvae of a fly, must also be ex- 

 cepted, as they wander about during* the day 

 and die on the surface. After heavy rain 

 succeeding dry weather, an astonishing num- 

 ber of dead worms may sometimes be seen 

 lying on the ground. Mr. Galton informs 

 me that on one such occasion (March, 1881), 

 the dead worms averaged one for every 

 two and a half paces in length on a walk in 

 Hyde Park, four paces in width. He counted 

 no less than 45 dead worms in one place in 

 a length of sixteen paces. From the facts 

 above given, it is not probable that these 

 worms could have been drowned, and if they 

 had been drowned they would have perished 

 in their burrows. I believe that they were 

 already sick, and that their deaths were 

 merely hastened by the ground being flooded. 

 It has often been said that under ordinary 

 circumstances healthy worms never, or very 

 rarely, completely leave their burrows at 

 night ; but this is an error, as White of Sel- 

 borne long ago knew. In the morning, after 

 there has been heavy rain, the film of mud 

 or of very fine sand over gravel-walks is often 



