780 REPORT OF COMMISSIONER OP FISH AND FISHERIES. [2] 



hered to the siphon cloth. This, however, was easily remedied by giving 

 the siphon bag a slight shake hourly. 



On the morning of the 7th I found a great many dijad eggs in both 

 apparatus, and the following day all were dead in the aquarium. I at- 

 tributed the mortality to the fact of this adhesion to the siphon cloth 

 and to the sediment in the water. 



On the 9th Colonel McDonald arrived at the station, aud after talk- 

 ing the matter over we concluded that there was too much motion. I 

 put 100,000 more eggs into the aquarium, using as little motion as pos- 

 sible, and entirely filtered the water. The eggs in the tub were still 

 doing well, although under exactly similar circumstances as those in 

 the aquarium, so I thought the advantage of the former over the latter 

 was due to the larger area. I then started a large tub, fitted up in the 

 same manner as before, with a fresh lot of eggs and a moderate circular 

 motion. They all did well until the 13th, when I found it was neces- 

 sary to do something else with them, as they were clotted together and 

 sunk to the bottom. The fish at this time could be seen distinctly. I 

 took them out and, after cleaning them off, placed them in a McDonald 

 jar and worked the same as with shad. I was also compelled to trans- 

 fer those in the large tub to jars, working with a small jet of water ap- 

 plied to the surface, which made them swing gently around the jar, but 

 not enough to drive them to the bottom. 



On the 15th all the eggs taken on the 5th, which were worked in the 

 aquarium for five days and afterwards transferred to jars, were dead; 

 but they were well developed aud would probably have hatched out in 

 a few days. 



On the 10th I was obliged to take all the eggs out of jars and aquaria 

 for the same reason as before, and I am convinced that cod eggs sink 

 to the bottom as they grow older and as the young fish begin to develop. 

 I then placed them in three jars, working one with top motion, one with 

 bottom motion, and the other with a combined motion of top and bot- 

 tom ; but this resulted, as before, in their gradually dying, and on the 

 eleventh day after they were taken all were dead. In one jar the eggs 

 were left to adhere constantly to the siphon bag for eight days. For 

 the first six days they did well, but after that they began dropping off, 

 and at the end of the eighth day they had all dropped off and were 

 dead. 1 tried the tubs once more with slightly altered conditions, but 

 the result was the same. In all the methods and motions tried a great 

 many of the eggs lived until the hearts of the young fish could be seen 

 to beat. 



Captain Chester also had two boxes fitted up, one with a copper 

 screen in the bottom, and in another he put two of the hatching jars, 

 but covered them with copper- wire screens. All of these experiments 

 resulted in naught, but the experiments had been continued long enough 

 to satisfy us that it was better than anything heretofore discovered. 

 In putting in the next lot of eggs Captain Chester used cheese-cloth 



