[3] EXPERIMENTS WITH SHAD EGGS. 785 



daj, when 1 fouutl tliem dyiug very fast, probably from the iini)ure 

 water caused by the can being closed. 



June 22,-1 arranged Cone No. 1 with the aerator attachment, and put 

 in 125,000 eggs taken the evening before. The same amount of water, 

 23 gallons, was used on this occasion as on the others. Cone No. 4 all 

 hatched and appeared in a very healthy condition. Out of the lot of 

 eggs in Cone No. 4 there were about 90,000 fish, making a very good 

 percentage. I took one-half of these fish jmd put them in Can No. 5, 

 running a smaller quantity of water than on any of the other cones. 

 There was no aerator attached to this cone. There were 18 gallons of 

 water per hour running in this cone. These cones were kept running 

 and were examined from day to day until June 25, when the fish were 

 deposited in the Potomac in good condition. 



Jiine 26. — On this morning I found the eggs in Cone No. 1 all hatched. 

 The eggs had been examined from day to day ; found to be about the 

 same as the cones hatched before. On this day I was directed to dis- 

 continue operation* at the navy-yard station, to move what fish I had 

 on hand, about 100,000, to the Smithsonian Institution, and to continue 

 my experiments there. The young fish were moved to the Smithsonian 

 on the morning of June 27, where they were placed in cones and cans. 

 In Cone No. 1, with aerator attachment, I placed 20,000 ; in Cone No. 2, 

 20,((00; in Can No. 1, with aerator attachment, 20,000; the balance were 

 placed in Can No. 2. My experiments consisted of one cone with aerator 

 attachment, running 23 gallons of water per hour ; Cone No. 2, with no 

 attachment, running 15 gallons of water per hour. This was afterwards 

 reduced to 10 gallons per hour. In Can No. 1 1 ran 15 gallons per hour 

 until the rubber hose conducting the water burst, during the night of 

 June 27, when, of course, the fish all died. In Can No. 2 there was no 

 change of water during the night. The next morning I found the fish 

 all dead. The cones were examined from day to day, and at this writ- 

 ing, July 3, the fish in Cone No. 1 are nearlj' all dead. The fish in Cone 

 No. 2 are looking well. They are seven days old to-day. 



From my experiments I have come to the following conclusions: 



When a small quantity of water is to be used in hatching it is abso- 

 lutely necessary to use the aerator to introduce the air with the water 

 at the bottom of cones in order to give the eggs the motion desired. 

 In every case where the aiirator was in use, and they were kept until the 

 fifth day, they commenced dying, and in twenty-four or forty-eight hours 

 all were dead. My opinion is that the violence of air-bubbles and water 

 weakened or wore them out. When it is desired to keep the fish in cones 

 for any length of time, and to use a small quantity of water, I should 

 advise that :i small quantity of water be run in the cone, as when it is 

 desired to use a limited supply of water a smaller quantity can be used 

 than with the aerator. In every case the experiment tried with the can 

 in which no change was given the fish proved disastrous in from six to 

 ten hours, according to the quantity of fish in the cans. 



Washington, D. C, July 3, 1880. 

 S. Mis. 110 50 



