96 DROPS OF WATER. 



can withdraw, and can also stretch themselves 

 out to a considerable length when actively em- 

 ployed. 8. uvella (Drop II. fig. 6), the only species, 

 has the form of a mulberry, and I have watched 

 the individuals when arrived at maturity separat- 

 ing from each other, and at last leaving nothing 

 but the shrivelled remains of their former habi- 

 tation : it is a most interesting genus, and is 

 fortunately not scarce. To show what astonish- 

 ing powers these little creatures possess, I will 

 relate a circumstance I witnessed. A large clus- 

 ter had evidently been injured by pressure, so 

 that half of its members appeared to be mis- 

 shapen and dead. The living end was actively 

 employed in turning round, and for some time 

 I could not comprehend what this action denoted; 



