INLAND FISHERIES, 23 



males aud females in these experiments were less than two inches 

 long and were undoubtedly of the set of 1899. 



On June 7, a larg-e number of specimens from the same locality 

 had extruded practically all their eg-g-s or sperm, some had ex- 

 truded a portion, and others were still full of sexual products. 



In connection with this observation there are two minor points 

 of interest namely, first, that the small clams spawned before the 

 larger ones ; and, second, in clams of the same size, those near high 

 water spawned before those at low water. 



In conclusion, and in answer to the original question, it may be 

 said with certainty' that clams spawn during the first year of their 

 life. 



Is there a second hreeding season ? 



Between the regular spawning season of June, 1899, and June, 

 1900, there was another distinct breeding season, probably in the 

 fall of 1899. The set resulting from this was first discovered in 

 Aijril, 1900, when the largest specimens were about one-quarter inch 

 long. The evidence that this was a fall set is that every specimen 

 had the surface of the shell next to the hinge corroded and dis- 

 tinctly marked off from the new growth. This condition is never 

 seen in the summer set, but would be accounted for if the clams 

 lay for months Avitli almost no growth. The mark persists in these 

 specimens until they are more than an inch long. By the tenth 

 of June some of these had grown to 30mm. in length and were as 

 long as many sexually mature year-old specimens. Photographs 

 of specimens taken May, 1900, are shown in figure 7. 



Is artificial fertilhat'ion of tJie clam j^ossibh and lyracticahle for oh- 

 taining spat in quantity f 



I have tried numerous experiments on the artificial fertilization 

 of clams, l)ut Avith small success. It has not been possible to in- 

 duce them to lay their eggs like the scallo^js, and when the eggs 

 are cut out and fertilized, only a small proportion, 10 per cent, 

 to 20 per cent., will develop. 



