— 30 - 



knowledge and all have heard of its being plowed out by the farmers 

 and picked up from the furrows unfortunately in part to be waste- 

 fully fed to hogs or chickens. Even in recent years, it has been 

 abundant enough so that during the past four years (1916-1919) the 

 beaches of jMorro, Pismo and Oceano furnished yearly over 150,000 

 individuals weighing on the average over 200 tons. 



Its heavy shell might protect it against the force of the surf but 

 another danger, perhaps even greater, threatens it. Only those who 

 know the beaches intimately realize to what an extent the sand is a 



Fig. 19. Digging Pismo clams, Oceano. Digger 

 returning with liis forlt and a "limit" of clams in 

 his "drag." 



changing thing. Pounded and scoured by the waves which act accord- 

 ing to the tide now at this level and now at that, the surface of the 

 beajch trodden by the bather which seems so hard and to the casual 

 eye so unchanging from day to day, is really in a state of constant 

 flux, being now cut down and now built up sometimes to a depth of a 

 few inches and sometimes to a foot or so. This and some of the work 

 that deals with the wave action has been already referred to. Often 

 during a month or an entire season one kind of action will predominate 

 and the diggers who daily frequent the beach and study it as a sailor 

 does the sea, can point out a stranded buoy or stump or rock now 

 bare, that last season was covered, or which now can barely be seen 

 though before it was conspicuous. Such erosion or filling amounting 

 to several feet is common. Below tides the sand is even more at the 

 mercy of the water. On the broad, gently shelving beaches where the 



