40 WESTERN SERIES OF READERS. 



But safety is not enough. A band of robbers 

 may be perfectly safe in a deep cave, but they can- 

 not stay there always, unless they are willing to 

 starve. So our little clam must have communica- 

 tion with the sea, and must get fresh supplies 

 from that great source of food. 



But he cannot conveniently come up out of his 

 burrow, for he is getting bigger every day, and 

 the hole by which he entered is too small to let 

 him out. However, he has no need to come out, 

 for he has two slender tubes attached to his body, 

 though they are grown together so as to look like 

 one. 



When the tide is out, he lies snug and quiet at 

 the bottom of his burrow, just waiting. By and 

 by he hears a faint splashing, and soon a cool 

 bath of salt water comes running down his little 

 burrow. He is happy now, for he knows that the 

 tide has risen, and that his quarters are well con- 

 cealed by the flowing water. So he sends up the 

 two tubes, or siphons as they are named, though 

 some people call them his neck, and opens their 

 ends in the clear water at the surface of the mud. 



Now, on his gills are thousands of very minute 

 hairs, called cilia, and he sets these cilia to lash- 

 ing in such a direction that the water is pulled 

 down one tube and forced up the other. What a 



