160 EOVING EARLY LIFE OF BALANUS. 



sight may often be witnessed in the rock-pools, 

 when they are of sufficient depth to cover the 

 balani, and are not exposed to the action of the 

 wind. 



With all their beauty, however, the balani are 

 uncongenial inhabitants of an aquarium, although 

 they add much to its appearance at first. They 

 soon become languid, their graceful cirrhi remain 

 half protruded from the shell, they then die, and 

 shortly exude such a detestably-scented gas, that 

 the surrounding water soon becomes unfit for the 

 respiration of the other inhabitants — they in their 

 turn die, and the whole aquarium is ruined. So, 

 present beauty must be sacrificed to ulterior 

 service ; and if any balani are growing on a rock 

 intended for the aquarium, they must be removed 

 before it is placed in the tank. 



They do not seem to be particular as to their 

 place of residence, for they may be found on 

 rocks, wooden piles, stones, and even on living 

 shells, of which they most afiect the limpet, 

 because it is not of migratory habits. 



It is a vrery remarkable fact, that although the 

 balanus never moves from the spot on which it 

 has taken up its habitation, and, indeed, is inca- 

 pable of any kind of locomotion, yet when very 

 young it was an active, wandering little creature, 



