MOLLUSCA 

 STUDY OF A LIVE FRESH-WATER CLAM OR MUSSEL 



1. Collecting. 



(1) Mussels may be found in the shallow water of our ponds 



and streams, where they are often partly embedded 

 in the sand or mud. 



(2) They may sometimes ''be obtained by a long-handled 



rake from the shore or from a boat."^ But the surest 

 plan is to don rubber boots and wade out after 

 them. 



(3) As soon as they are captured place them in water and 



carry them to the laboratory, and put them in the 

 tank with a few inches of sand and several inches of 

 water in the bottom. 



2. Laboratory Study. 

 (1) Locomotion. 



(a) Watch carefully to discover just how a clam moves 



itself along. 



(b) Does it leave a track? If so, describe it. 



(c) What is the direction of its progression? 



(d) What is the rate of its progression? 



(e) Place your finger in the sand across the path in front 

 of the mussel and, by allowing it to pass over your 

 finger, find out how the "foot" is used. 



(f) Quickly pick up a mussel in locomotion. Note its 

 foot. What does it do? 



(g) Lay a clam on its side on a piece of glass or smooth 

 wood. 



(1) What does it do? 



(2) Can it resume its natural position and creep away? 



Explain. 



^ Galloway's " Zoology." 

 260 



