200 



ZOOLOGY 



medusse produce eggs and sperms. Their reproduction is sexual, 

 as was the reproduction by means of eggs and sperms from the 

 prothallus of the fern. So we have in animals, as well as in 

 plants, an alternation of generations. 



Sea Anemone. — Those who have visited our New England coast are 

 famihar with another coelenterate called the sea anemone. This animal 

 gets its name from the fact that, seen in a little rocky pool along the shore, 

 it looks like a beautiful flower of a golden yellow or red color. The body 

 of the sea anemone is like the hydra, a column attached at one end. The 



Sea anemone. About natural size. The right-hand specimen is expanded. Note the mouth 

 surrounded by the tentacles. The left-hand specimen is contracted. From model at the 

 American Museum of Natural History. 



free end is provided with a mouth surrounded with a great number of 

 tentacles. These, when expanded, look like the petals of a flower. The 

 sea anemone is a very voracious flower, for by means of the batteries of 

 stinging cells in its tentacles it is able to catch and devour fishes and other 

 animals almost as large as itself. When disturbed or irritated, the animal, 

 like the hydra, contracts into a slimy ball. 



Although the sea anemone is like a large hydra in appearance, its Interior 

 is different. The hollow digestive cavity contains a number of partitions 

 more or less complete, which run from the outer wall toward the middle 



