66 HABITS OF WORMS. Chap. II. 



plugging-up process may serve for all the 

 above purposes. 



Whatever the motive may be, it appears 

 that worms much dislike leaving the mouths 

 of their burrows open. Nevertheless they 

 will reopen them at night, whether or not 

 they can afterwards close them. Numerous 

 open burrows may be seen on recently-dug 

 ground, for in this case the worms eject their 

 castings in cavities left in the ground, or in 

 the old burrows, instead of piling them over 

 the mouths of their burrows, and they cannot 

 collect objects on the surface by which the 

 mouths might be protected. So again on a 

 recently disinterred pavement of a Roman 

 villa at Abinger (hereafter to be described) 

 the worms pertinaciously opened their bur- 

 rows almost every night, when these had 

 been closed by being trampled on, although 

 they were rarely able to find a few minute 

 stones wherewith to protect them. 



Intelligence shown by worms in their manner 

 of plugging up their burrows. — If a man had to 

 plug up a small cylindrical hole, with such 

 objects as leaves, petioles or twigs, he would 

 drag or push them in by their pointed ends ; 



