24 INLAND FISHERIES. 



While, therefore, it caunot be said, at present, that artificial fer- 

 tilization in case of clams is impossible, the results so far are not 

 encouraging-. 



Do cla-ins change their sex as they groio older f 



This question has been raised in regard to the clam and is a 

 legitimate one, inasmuch as several accounts have been given by 

 verj'- high authorities that in certain other animals this curious 

 phenomenon occurs. In these cases the animal is at first a male, 

 and later a female. Between the two conditions there is a herma- 

 phrodite stage according the recent researches of W. M. Wheeler 

 on one of these animals, Myzostoma. This animal is potentially 

 hermaphrodite from the first, but in the early stages the eggs do 

 not ripen, although the sperm does, so that they are practically 

 males. 



A large number of clams have been very carefully examined 

 by means of microscopic sections, or by a microscopic examin- 

 ation of the liA'ing specimens. These observations may later be 

 published in detail in connection with appropriate researches, 

 but the general concliision arrived at is that there is no such 

 phenomenon present among the clams, or, in other words, that 

 the clams do not change their sex. 



In the examination of the living specimens there seemed to be 

 evidence of occasional hermaphroditism, but^it is probable that it 

 rarely, if ever, occurs. 



y^hat are the hest methods of obtaining yoxing clams for jjlant'mg ? 



The importance of obtaining spat in quantity is fully recognized 

 by the oyster culturists, and immense sums of money have been 

 expended in experiments in this line. For successful clam-culture 

 it is quite essential that the small clams be obtained in abundance 

 and with tolerable certainty. 



In the case of both clams and oysters the abundance of the set is 

 subject to great variation from year to year. In the year 1899, for 

 example, the clam-set was unusually large in nearly all parts of 



