224 Starfish and Daisy [THIRD WEEK 



radial symmetry of its stalked ancestors. Pick up your 

 starfish, carry it to the nearest field, and pluck a daisy 

 close to the head. How interesting the comparison be- 

 comes, now that the knowledge of its meaning is plain. 

 Anything which grows fast upon a single immovable stem 

 tends to grow equally in all directions. We need not stop 

 here, for we may include sea anemones and corals, those 

 most marvellously coloured flowers of the sea, which grow 

 upon a short, thick stalk and send out their tentacles 

 equally in all directions. And many of the jelly-fish 

 which throb along close beneath the surface swells were in 

 their youth each a section of a pile of saucer-like indi- 

 viduals, which were fastened by a single stalk to some 

 shell or piece of coral. 



We will remember that it was suggested that the theo- 

 retical daisy would soon alter its shape after it entered 

 upon active life. This is plainly seen in the starfish, 

 although at first glance the creature seems as radially 

 symmetrical as a wheel. But at one side of the body, 

 between two of the arms, is a tiny perforated plate, serving 

 to strain the water which enters the body, and thus the 

 circular tendency is broken, and a beginning made toward 

 right and left handedness. In certain sea-urchins, which 

 are really starfishes with the gaps between the arms filled 

 up, the body is elongated, and thus the head and tail 

 conditions of all animals higher in the scale of life are 

 represented. 



