42 REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



in the amount of spawn and the chances of fertihzation would fol- 

 low a general increase in the abundance of adult clams is self evi- 

 dent. Experiments in artificial fertilization have been tried many 

 times and a sufficient number of eggs were fertilized for working out 

 the early stages of development, but as a practical method it does 

 not yet give promise of success. 



The Increase in the Production of the Set. — A good deal, we believe, 

 can be accomplished at this point. It is a significant fact that the 

 water is, at certain times of the year, swarming with clam larvae 

 ready to set. A phenomenon witnessed almost every year of re- 

 markably thick sets in certain limited areas, and the fact that 

 equally thick sets have been caught by artificial contrivances in 

 places where the natural set was sparse, shows that favorable con- 

 ditions at the place of setting is the most important factor, and 

 probably one which may be, to a certain extent, controlled. 



Of the spat collectors referred to, two forms have worked suc- 

 cessfully. The first, described more fully in the report for 1900, 

 consisted of a small, square, bottomless box, 12 by 14 inches in diam- 

 eter, set firmly into the ground near the low-water mark, and cov- 

 ered with a fine galvanized wire netting, "pearl cloth." The 

 swimming fry apparently hit upon the netting and fall to the ground, 

 and, if they rise again as far as the netting, they are apt to be again 

 precipitated. In this box we caught about 15,000 clams. Another 

 successful form is that installed at Mr. Alexander's estate, on 

 Rumstick Point (described and figured in the last report). It con- 

 sists of a sand-filled box with a wooden cover provided with a 

 window of pearl cloth and bored with numerous small holes. A 

 large number of clams have been caught in this apparatus. 



The Protection of Spatvn and Swimming Fry. — To protect the 

 spawn and swimming fry from adverse physical conditions and 

 natural enemies is, as far as we know, impossible. These micro- 

 scopic creatures are carried hither and thither, according to the con- 

 dition of tides and winds, light and darkness, heat and cold — for 

 they doubtless rise and sink in response to changes in light and in 



