2i6 Dzvellcrs of the Sea and Shore 



stantly It is arrested in its course aiiel wafted at once 

 toward the ever-waiting mouth. 



Highest of all worms are the segmented forms, and 

 the highest of these are the wandering, or free-swim- 

 ming bristle bearers. And among them are the most 

 beautiful. The attractiveness of two types. Aphrodite 

 and Nereis, has already been dwelt on in an earlier 

 chapter, so that feature needs no further comment 

 here. Nereis (A^. virens) , however, merits attention 

 for other reasons quite as much as for her beauty. She 

 is easily reared in the indoor aquarium. The activities 

 of few other inmates are more interesting to watch than 

 are hers. When young the worm wmU make a nest in 

 old shells or under stones; sometimes it will seek a 

 frond of Ulva for this purpose. After growing too 

 large for such quarters — a length of fifteen inches being 

 not uncommon for this animal — she burrows into the 

 sand or mud where she builds another. Her retreat 

 is a tunnel, the lining of which is composed of an ad- 

 hesive mucus that binds the walls. Quite often it Is 

 built In such a manner that she has egress at either end, 

 thus facilitating her escape when pressed by an enemy. 

 Notwithstandina that the diameter of the tunnel Is 

 approximately that of her body, she can turn around 

 In it with remarkable ease and rapidity. Here she 

 remains hidden throughout the day, seldom venturing 

 to extend more than half her length beyond the open- 

 ing. She loves the night. It is then that she becomes 

 quite active. Leaving her burrow she will wander 

 about for hours, and being a fairly fast swimmer, as 

 well as an exceedingly graceful one, the distance she 

 covers Is not inconsiderable. In the tanks of my lab- 



