OF SEA-ANEMONES. 68 



most important condition of health, or, should un- 

 foreseen accidents arise, would be totally unable to 

 meet the emergency. 



With regard to our sea-anemones, the " common 

 sense," then, of the matter is simply this : they, 

 being animals, take in large quantities of the oxygen 

 which exists both in the water and in the air. This 

 gas is as necessary to their existence as to ours, 

 and when they are deprived of it they languish and 

 die, as we do in close rooms and pestilential courts. 

 They feed on the animalcules which abound in the 

 sea-water, consequently, if we continually filter the 

 water, although we may purify it from all decaying 

 and refuse matter, we deprive our captives of a large 

 amount of the food which is also necessary to them.* 

 The larger anemones (especially the thick-skmned) 

 seem to require more sustenance than the minute 

 animalcules can afford them, and in their native 

 depths they devour crabs, shell-fish and the like, 



* The question then arises, how do they flourish in Mr. Gosse's 

 manufactured sea-water? The fact is indubitable; how do we 

 account for it ? Mr. Gosse puts in his weed some days before he 

 puts in his animals. Now, if we place some fresh water in a clean 

 glass vessel, and thi'ow in a few clusters of pond-weed or the like, in 

 a few days the microscope will disclose countless numbers of ani- 

 malcules which did not exist before. Doubtless then, in both cases, 

 they spring from the invisible eggs or spores which abound in the 

 atmosphere and the water, £ind which vi\'ify under the proper 

 conditions of existence. So mites are bom in mouldy chee<e. 

 " eels" in paste, \inegar, and so forth. 



G 2 



