FOOD. 37 



ments on the subject; and so far as I have proceeded, 

 my results agree with those of Mr. Lloyd ; except 

 that I have found a seclusion of several months 

 necessary. This was, however, in the winter. 



Cloudiness may often be removed by the action 

 of living animals. The Bivalve Mollusca collect 

 the organic particles that float in the water, as the 

 currents pass over their capacious gills, and either 

 feed on them, or consolidate them into cylindrical 

 rolls, which fall to the bottom, enveloped in mucus. 

 Hence they are of great service in making turbid 

 water limpid and bright. An oyster or two, 

 according to the size of the vessel, will answer 

 exceedingly well, as they are very hardy, and can 

 be procured alive anywhere, and almost at all 

 seasons. 



Food. — I am continually asked, hoio^ with what, 

 and how often I feed my animals. My invariable 

 reply is,— *'Not at all." I do not find that tliey 

 need any supply but what they procure for them- 

 selves. In a well-stocked and established Tank, 

 the vegetable-feeders find a sufficient pabulum in 

 the ever-growing weed ; and all the carnivorous 

 species are maintained in condition by the hosts of 

 Infusoria and Entomosteaca that are always 

 swarming. The lens shows these tiny creatures to 

 be abundant in every collection of water that has 

 been kept for a short time ; and, as they breed very 

 fast, their increase is sufficient to meet the demands 

 of their superiors in organization. At least, I find 

 that my well-filled Tanks need no other supply 

 than this, and what the more predatory kinds 

 occasionally obtain by the death of their fellows. 

 For amusement, indeed, the Actiniae, the Madre- 

 pores, the Prawns, and the Crabs, may be fed; 



