SEA-ANEMONES. 



3 



formerly fashionable, if one such could be made to stand of itself erect, 

 and have the frill around the upper end to project in a circle. But we 

 must be more particular than this. The upright part, that which is 

 called by naturalists the column, is hollow, like a sack. Its base is 

 really a sucking-surface, enabling it to adhere to any hard object. 

 By this sucking base it can glide, or travel along, much like a snail. 



Fig. l.a, Ap.achnactis Albida; b. Actinia Rosea. 



And as it thus moves, it can keep its flower spread out, and its many 

 tentacles in constant play in fact, fishing on the way. Their move- 

 ment is, however, very slow. Indeed, a " snail-pace " would be alarm- 

 ingly fast for an actinia. We have watched them attentively, and 

 have found that an inch in an hour was a very satisfactory perform- 

 ance. At the top is an opening, called the oral cavity, which, in the 

 rosea, is surrounded just inside with a beading of little dots. This 

 opening may be called the mouth, because the food is passed at this 

 aperture into the stomach, which is a cylindrical sac, suspended 

 below, and reaching about half-way down the great cavity of the col- 

 umn. Around the oral cavity, and external to it, is a plain surface, 

 which is technically known as the " disk." Around the disk, on its 

 outer edge, is the fringe of tentacles. Each one of these is a little 

 hollow cylinder, opening into the great cavity of the column imme- 

 diately Tinder the edge of the disk. In fact, these tentacles, or feelers, 

 connect with the interior of the stem of the Anemone, just as the fin- 

 gers of a glove do with the interior of the same. We should also 

 mention that, at the bottom of the sac, which is here called the 

 stomach, is an opening into the general cavity. Now, around this 

 suspended stomach, that is, between its outer wall and the inner wall 

 of the column, is a system of compartments in series. These vary as 

 to number in the different species. By looking at the cut showing a 

 cross-section of an actinia's stem, we observe that six of these com- 

 partments are complete, and reach from the stomach to the walls of 



