72 HABITS OF WOKMS. Chap. II. 



chiefly due to the curling in of the margins. 

 Out of 36 fallen leaves on another bed, in 

 which different varieties of the Rhododendron 

 grew, only 17 were narrower towards the 

 base than towards the apex. My son William, 

 who first called my attention to this case, 

 picked up 237 fallen leaves in his garden 

 (where the Rhododendron grows in the 

 natural soil) and of these 65 per cent, could 

 have been drawn by worms into their bur- 

 rows more easily by the base or foot-stalk 

 than by the tip ; and this was partly due to 

 the shape of the leaf and in a less degree 

 to the curling in of the margins: 27 per 

 cent, could have been drawn in more easily 

 by the tip than by the base : and 8 per cent, 

 with about equal ease by either end. The 

 shape of a fallen leaf ought to be judged 

 of before one end has been drawn into a 

 burrow, for after this has happened, the free 

 end, whether it be the base or apex, will dry 

 more quickly than the end embedded in the 

 damp ground ; and the exposed margins of 

 the free end will consequently tend to become 

 more curled inwards than they were when 

 the leaf was first seized by the worm. My 

 son found 91 leaves which had been dragged 



