04 A MANUAL 



consequent!}^ we must indulge them with such deli- 

 cacies whilst in captivity, or they will gradually fall 

 into an atrophj^, dwindle awa}^ almost imperceptibly, 

 and after the lapse of many months, though they be 

 apparently in perfect health and in full bloom, will 

 have diminished to a half or a quarter of that size 

 in which they rejoiced when we chiselled them out 

 of their rock-pools. 



All the anemones throw off daily a coat of slime, 

 and this is chiefly observable in the case of the 

 common species ; they also cast away the refuse of 

 their food in small pellets, which are ejected from 

 their mouths, linger among the tentacles, and fall to 

 the base of the rock on which they adhere. If we 

 keep sea-weed amongst them, this too decays and 

 forms a slimy deposit. The minute Serpulas, Ne- 

 reids, and other animals wdiich inhabit the stones we 

 place in our aquariums, die speedily and corrupt the 

 water. Now the Marine Board of Health disposes 

 of all these nuisances in an instant : up rushes a 

 large wave or a heavy under-current, and sweeps 

 away every particle of decaying matter, dashing it 

 on the rocks again and again, until, by constant 

 contact with the air, the whole mass of impurity is 

 thoroughly purified. 



Every Avave which breaks upon the beach, or 

 curls its foam-flecked crest in multitudinous light- 

 spangles far out at sea, contributes somewhat to this 

 great sanatory work, and adds its offering of vital 

 air to the mighty ocean world. 



