green or even white, perhaps tinted with pink or lav- 

 ender. The aggregated anemone, green with pink or 

 lavender markings, is by far the more abundant of 

 the two species, but it has a less extensive range and 

 peters out south of San Luis Obispo and north of 

 British Columbia. Aggregated anemones live in 

 densely crowded beds higher up on the shore, often 

 attached to rock in sand; they survive much sand 

 deposition and scour. Perhaps they are helped by 

 their patchy armor of adhering pieces of shell and 

 gravel, which makes them look so much like the 

 background that one often sits or walks on them un- 

 wittingly and then hears — or feels — their squashy 

 wetness. Both species of Anthopleuia. as well as 

 many other anemones, have vertical rows of warts 

 that cover the column. In some anemones these 

 have no function we can discover, but in Antho- 

 pleiira, Tealia. Biiiioclcictis (Plate 21). and others 

 the protuberances are glandular and sticky, and hold 

 sand or shell fragments close about the column. 



If green anemones that contain green algal cells 

 are more deeply colored in full light than in shaded 

 areas, we can see why this should be so, but what of 

 other green anemones or the green varieties of Ac- 

 tinia that have no algae? These are also found to be 

 more densely colored in brighter situations, and so 

 are many red dahlia anemones. If we explain this by 

 saying that the pigment acts as a screen against 

 light too strong for the delicate tissues, this will not 

 do for Metridiiim senile. The ones examined on Brit- 

 ish shores are, if anything, more likely to be white in 

 the most lighted situations. This species of plumose 

 anemone has an especially striking array of color 

 varieties, even in those found living side by side. Fox 

 and Pantin, working at Cambridge with specimens 

 of Metridiiim from all over England and from Scot- 

 land, described the varieties as white, simple red. 

 simple brown, brown with gray, simple gray, red 

 with gray, red with brown, and red with brown with 

 gray. The notation "simple red" covered red, orange, 

 or salmon-pink hues, or even yellowish varieties, 

 since these shades depend upon the intensity of the 

 red pigment, or perhaps several pigments. The con- 

 clusion they drew was that the color varieties may be 

 due to random variations in heredity and may be re- 

 lated to biological processes taking place within the 

 animal. When the resulting colors are vivid, they may 

 have no special value as coloration, but indicate only 

 that bright color is no great handicap to an anemone 

 and is therefore not eliminated by natural selection, 

 as perhaps it is in drab-colored groups that match 

 their surroundings. In some anemones the color is 

 clearly related to the food supply. If the tentacles of 

 a red Actinia equina are amputated and the animal 

 eats the usual diet of red shrimp, the tentacles grow 

 back red. If instead the anemone is fed on colorless 



The aggregated anemone of the American Pacific 

 coast, Anthopleura elc^antissima, in the final stage of 

 reproduction bv body rupture. Only a thin strand of 

 tissue still connects the two daughter anemones. 

 (California. Woody Williams) 



pieces of fish, the regenerated tentacles are colorless. 



The responses of anemones are not always the 

 ones we would make to the same kinds of stimula- 

 tion, but they do seem suited to the life of an anem- 

 one. When taken into the laboratory by C. F. A. 

 Pantin and his many students at Cambridge, Calli- 

 actis parasitica appears undisturbed by contact with 

 an electrically heated wire that burns the skin of the 

 column. Yet the tentacles twitch at the slightest tap 

 on the walls of the aquarium or when waves are set 

 up in the water by any object, whether or not it is an 

 offering of food. To mechanical prodding the disk 

 and tentacles are four thousand times as sensitive as 

 the column. 



Often it is impossible to pry an anemone loose 

 without inflicting injury or leaving pieces behind. In 

 nature there are species that treat themselves in this 

 same way, either because of the roughness of the 

 rock over which they move or because of incoordi- 

 nation. The plumose anemone is one of these, and it 

 turns tragedy into triumph, because the fragments 



[107 



