Chap. VII. CONCLUSION. 315 



Worms are poorly provided with sense- 

 organs, for they cannot be said to see, 

 although they can just distinguish between 

 light and darkness ; they are completely deaf, 

 and have only a feeble power of smell ; the 

 sense of touch alone is well developed. They 

 can therefore learn but little about the outside 

 world, and it is surprising that they should 

 exhibit some skill in linino- their burrows 

 with their castings and with leaves, and in 

 the case of some species in piling up their 

 castings into tower-like constructions. But it 

 is far more surprising that they should ap- 

 parently exhibit some degree of intelligence 

 instead of a mere blind instinctive impulse, in 

 their manner of plugging up the mouths of 

 their burrows. They act in nearly the same 

 manner as would a man, who had to close a 

 cylindrical tube with different kinds of leaves, 

 petioles, triangles of paper, &c, for they 

 commonly seize such objects by their pointed 

 ends. But with thin objects a certain number 

 are drawn in by their broader ends. They do 

 not act in the same unvarying manner in all 

 cases, as do most of the lower animals ; for 

 instance, they do not drag in leaves by their 



