124 SEA-SIDE STUDIES. 



it can secure. Not so. For granting — what, in fact, I 

 sturdily dispute— that the Flytrap is in no way dependent 

 upon such insect food as may fall into its clutch, we shall 

 still obsei-ve the Actinia in similar independence. Keep the 

 water free from all visible food, and the Actiniae continue 

 to flourish and propagate just as if they daily clutched an 

 unhappy worm. The fact is well known, and is currently, 

 but erroneously, adduced as illustration of the animal's 

 power of fasting. But there is no fasting in tlie matter. 

 In this water free from visible aliment there is abundance 

 of invisible aliment, — infusoria, spores, organic particles, 

 &c. which the animal assimilates, much in the same way as 

 plants assimilate the organic material diffused through the 

 soil and atmosphere. Filter the water carefully, and remove 

 from it all growing vegetation, and you will find the animal 

 speedily dying, however freely oxygen may be supplied. It 

 is on this account that when we make artificial sea-water, 

 it is necessary to allow algse to grow in it for some two or 

 three weeks before putting in the animals ; the water be- 

 comes charged with organic material. 



Mere sensibility and capture of food, therefore, are not 

 the distinguishing marks we seek, since the plant is found 

 to possess them as perfectly as the animal. Is spontaneous 

 locomotion a sufficient mark ? No ; and for these two 

 reasons : Some anhnals have no such power ; some plants, 

 and all .spores, have it. There are animals which no 

 botanist has ever claimed — the Ascidians, for example, 

 which can scarcely be said to exhibit any motion at all (the 

 rhythmic contraction and expansion of their orifices not 



