244 THE WEALTH OF THE SEA 



is carried out in a limited way in New England. 

 Small areas are found bn almost every flat where 

 small soft clams are found in enormous numbers at 

 certain seasons of the year. Sometimes as many as 

 two thousand seed-clams per square foot of surface 

 are obtained by washing the sand or mud through a 

 cradle-shaped sieve. Seed-clams obtained in this way 

 are planted on suitable tidal flats, and grow to 

 market size within a year or two. 



A somewhat similar system of culture has been 

 suggested for the hard clam but has never proved 

 profitable. Box spat collectors are used which some- 

 times catch as many as seventy-five young hard clams 

 per square foot of bottom, but as a rule the catch 

 is insufficient to warrant the requisite expenditure of 

 labor. 



The history of the soft clam industry is quite 

 similar to that of most of our fishery industries and 

 may be summarized in a single sentence: The sup- 

 posedly inexhaustible supplies, rapidly exhausted by 

 over-fishing, were saved from complete exhaustion by 

 conservation and culture. The period of plenty ex- 

 tended from colonial times to about 1875, when im- 

 proved transportation facilities opened up larger 

 markets. The over-fishing that followed soon depleted 

 many of the finest beds, and, by the beginning of the 

 twentieth century, much attention was given to re- 

 stocking the beds. 



Soft clams are dug both on exposed tidal flats and 

 on flats covered with shallow water. Submerged clams 

 are dug with a very large clam hoe called a sea-horse, 



