3H 



THE POPULAR SCIENCE MONTHLY. 



On various parts of the 

 sea - anemones, and of all 

 other polyps, especially on 

 their tentacles or fringes, 

 there are very remarkable 

 objects called cnidae, or las- 

 so-cells, like those on jelly- 

 fishes, each cell being less 

 than one two-hundredths of 

 an inch in length. In each 

 there is a long, slender, coil- 

 ed, and wonderfully - con- 

 structed thread, which can 

 be instantly darted forth, 

 paralyzing any little animal 

 which it strikes ; and thus 

 the hungry polyp secures 

 its food. 



On the vertical parti- 

 tions above mentioned the 

 eggs are borne. These pass 

 out into the water through 

 the mouth. The newly- 

 hatched anemone is oval in 

 form, and swims freely about 

 in the water by means of 

 exceedingl}- delicate fringes 

 called vibratile cilia. After 

 a time it quits this roving 

 life, attaches itseK to the 

 surface of the rocks, and 

 grows into the form and 

 size of the parent. 



Sea - anemones have no 

 proper nervous system. The 

 sense of touch is distributed 

 throughout the whole ani- 

 mal. It will, therefore, ap- 

 pear as a remarkable state- 

 ment that some kinds have 

 quite definitely-formed eyes. These are seen in some tropical species 

 just outside of the tentacles, and according to Dana each of these eyes 

 has a crystalline lens and an optic nerve ! 



Sea-anemones readily reproduce lost parts. If one is quickly torn 

 from a rock, parts of the foot remain attached to the rock, and in many 

 cases each portion thus left will become a perfect sea-anemone ! 



Sea-anemones vary greatly in size. Some species are only a frac- 



