20 NEW YORK STATE MUSEUM 



beerTpossible to visit these beds a few times during the summer, 

 the results in the case of many lower beds would undoubtedly 

 have been different. 



In pots still lower down, all of which were covered with Ulva, 

 the growth was much the same as in the fifth — from 80^ to 100^ 

 increase. 



In this line of pots, then, the fact is demonstrated that between 

 tide lines, hard clams 1.25 inches long may increase 2.5 times or 

 more in volume in half a year. Localities more favorable for their 

 growth could easily be found. If experiments were made on a 

 large scale, I should expect to get a more rapid average growth 

 even where the forms were exposed at low tide, and a much greater 

 increase on bottoms which are never exposed. As it is, this growth 

 as compared with that of the oyster is marvelously rapid, just as 

 it is in the soft clam. 



It should be noticed that we are not attempting to make extended 

 generalizations on the data given by four or five individual clams. 

 Two clams side by side will not increase at the same rate. It is 

 possible that one might grow twice as fast as another. But, if we 

 had a single case in which we were certain of the amount of increase, 

 it would assuredly indicate the possibilities of growth, and the 

 chances are that it would not by any -means be the limit of 

 possibility. 



On the other hand, when we compare the growth in pots i, 2 and 

 3., and find a progressive increase from the higher to the lower pot 

 — an increase of 145^, I54/^ and 172^ — our induction is founded 

 on insufficient data, and really means nothing. The result is as we 

 should expect it,- but it may be entirely accidental. But it is sug- 

 gestive, and, if it were possible to observe many rows of clams 

 similarly placed, we might reasonably expect to establish it. 

 Unfortunately it has not been possible to do this. 



The simple case of the line of flowerpots has been spoken of 

 first because it was more or less typical of the results obtained in 

 many small beds planted under similar conditions. Many hundreds 

 of clams, after being carefully measured, were segregated into 

 groups according to length and planted together. Their growth 

 substantiates the results obtained in the flowerpots. 



