VENUS MERCENARIA I7 



Another serious hindrance to the growth of clams is the presence 

 of the seaweeds, Ulva (sea lettuce) and Enteromorpha which, 

 during the greater part of the year, grow profusely after their 

 attachment to large pebbles or other solid bodies on the bottom. 

 Not only the larger stones on these beds, but, especially, the wire 

 cages which were sunk into the bottom, were in December 

 more or less completely covered by them. In extended experi- 

 ments on the growth of the soft clam, Mya, the same difficulty 

 was met with in many localities. The masses of weed, flattened 

 out on the bottom by the tide currents, greatly hinder the clams 

 underneath from obtaining from the w^ater their needed food. 

 My experiments with both forms show that this condition is 

 detrimental to the best results. If one were free to select 

 sandy ground which would afford no means of attachment, this 

 difficulty would not appear. 



These matters are spoken of in detail because the results which 

 will be given should, without doubt, have been far greater. Any 

 one with rights to certain parts of a beach, who could watch his 

 beds at all times of the year, could, with very little labor, prevent 

 these drawbacks. 



Still another difficulty attending the work at Cold Spring was 

 the fact that it was almost impossible to obtain clams small enough 

 for planting. None were to be had in this locality. A number 

 were sent from Jamesport, L. I., but most of them were of 

 marketable size, and hence too large for the most important part 

 of the experiment. The smaller ones came from New Bedford 

 Mass., and these had perhaps previously been received from Edgar- 

 town. It must however be said that the hard clam, like the oyster 

 and quite unlike the soft clam, Mya, will live for many days, and 

 even for weeks, after being removed from the water during the 

 hot summer time, without apparent injury. The soft clam may be 

 preserved in this way for a long time during the winter, and very 

 small individuals may safely stand much exposure in hot weather; 

 but the larger forms of this species succumb after a short time. 

 The tenacity of life in the small Venus may also be greater tha,n 

 in the adult, but nothing is known in regard to it. 



