50 Life and Immortality. 



the facts already given, that they would have perished in 

 their burrows. 



After there has been a heavy rain the film of mud or of 

 very fine sand to be seen over gravel-walks in the morning 

 is often distinctly marked with the tracks of worms. From 

 May to August, inclusive, this has been noticed when the 

 months have been wet. Very few dead worms are anywhere 

 to be seen on these occasions, although the walks are 

 marked with innumerable tracks, five tracks often being 

 counted crossing a space of only an inch square, which 

 could be traced either to or from the mouths of the burrows 

 in the gravel-walks for distances varying from three to 

 fifteen yards, but no two tracks being seen to lead to the 

 same burrow. It is not likely, from what is known of the 

 sense-organs of these animals, that a worm could find its 

 way back to its burrow after having once left it. They 

 leave their burrows, it would seem, on a voyage of discovery, 

 and thus they find new sites for the exercise of their powers. 

 For hours together they may often be seen lying almost 

 motionless beneath the mouths of their burrows. But let 

 the ejected earth or rubbish over their burrows be suddenly 

 removed and the end of the worm's body may be seen 

 rapidly retreating. 



This habit of lying near the surface leads to their destruc- 

 tion to an immense extent, for, at certain seasons of the year, 

 the robins and blackbirds that visit our lawns in the country 

 may be observed drawing out of their holes an astonishing 

 number of worms, which could not be done unless they lay 

 close to the surface. But what brings the worms to the sur- 

 face ? This is a question whose answer cannot be positively 

 asserted. It is not probable that they behave in this manner 

 for the purpose of breathing fresh air, for it has been seen 

 that they can live a long time under water. That they are 

 there for the sake of warmth, especially in the morning, is a 

 more reasonable supposition, which seems to be confirmed 

 by the fact that they often coat the mouths of their burrows 



