288 Our Food Mollusks 



Experiments on such dense segregations of clams have 

 also revealed the fact that if numbers are reduced by dig- 

 ging, the remaining individuals begin to grow. The 

 conclusion is that the judicious and intelligent digging 

 of a clam bed is beneficial to it. All clammers will agree 

 with this statement. It is the same condition that all are 

 familiar with in a garden of vegetables. Lettuce plants 

 or radishes will fail to develop if too closely crowded. A 

 densely planted bed must be thinned in order to do well. 

 The real difficulty on our natural clam beds has been 

 that no one has cared to thin the garden and transplant 

 the superfluous individuals on barren ground for fear 

 he would receive no return for his labor; and this fear, of 

 course, has its justification. Such an improvement over 

 the process of nature would be effected if the clammer 

 were given the same lawful right to a bit of beach that 

 he has to his vegetable garden, or that the oysterman 

 has finally succeeded in obtaining in the deeper water 

 of many of the coast states for his oyster beds. It is a 

 short-sighted policy that denies such rights to citizens 

 who desire to make productive, tracts that are now waste 

 places. 



It will be remembered that one of the most important 

 conditions governing the existence of the oyster is the 

 salinity of the water. The process of reproduction espe- 

 cially, depends on a proper degree of saltness, and its 

 range apparently is confined within rather narrow limits. 

 With Mya, these limits are very much wider. Clams 

 will grow and reproduce normally in water almost as salt 

 as that of the open sea, as well as in that which is nearly 

 fresh. The limits of salinity where this has been ob- 

 served are 1.024 an d 1.005, these being the averages of 

 several observations made during the summer while re- 



