XIV.-REPORT OF EXPERIMENTS FOR DETERMINING THE 

 SMALLEST AMOUNT OF WATER IN WHICH YOUNG SHAD AND 

 EGGS CAN BE KEPT. 



By Frank N. Clark. 



June 8, 1880, I was requested to conduct a series of experiments at 

 the sbad-hatching station at Washington navy-yard, and to use as small 

 a quantity of water as possible both for the eggs and young fish. I ac- 

 cordingly arranged one of the cones with an aerator attachment for Ex- 

 periment No. 1. 



June 9. — In the morning I placed in Cone No. 1 a portion of the eggs 

 taken the evening before (125,000), and also placed in Cone No. 2 the 

 same number. I commenced on Cone No. 1 by running 35 gallons of 

 water per hour. On Cone No. 2 there were 218 gallons per hour. The 

 aerator attached to No. 1 was doing the same work the larger amount 

 of water was doing in Cone No. 2. In the course of the day I reduced 

 the amount of water in Cone No. 1 to 23 gallous per hour, and found the 

 eggs had equally as good a motion as with the larger amount of water. 

 The motion of eggs in Cone No. 1 was considered as good as in No. 2. 



June 10. — Eggs were examined in both cones and found to be equally 

 as good in Cone No. 1 as in No. 2. 



June 11. — Eggs were examined in both cones. In Cone No. 1, with 

 aerator attachment, I found more fungoid growth on the unimpregnated 

 eggs than in No. 2. They were, however, kept free from the good eggs 

 by the force of air and water. In cones of eggs I have worked for the 

 last few years I have frequently-found eggs with the fungoid growth 

 to attach themselves to the good eggs. It Avas especially so when the 

 water was quite warm. I have always found it necessary in such cases 

 to add a greater flow of water. 



June 12.— The fish were all out and appeared in as healthy a condi- 

 tion in Cone No. 1 as in No. 2. So far I have been unable to uote any 

 difference in the eggs or in their hatching other than is mentioned in 

 this report. In the evening of this day I removed 25,000 fish from each 

 cone, leaving 75,000 in each of the cones, with same amounts of water 

 (23 and 218 gallons). I find the fish in Cone No. 1 are not forced against 

 the perforated tin edges as in Cone No. 2. Accordingly it is not neces- 

 sary to attend to them as in No, 2, where it was absolutely necessary to 

 brush the fish away from the edges at least once in an hour to keep them 

 from filling the perforated tin and running over the top of the cone. 

 This I think one great advantage. 



Jiinel^. — Fish were examined ; found them equally as good in No. 1 

 as in No, 2. TIk^ force t>t' air in Cono No, 1 seems to be rather violent 

 1 1] 7.^:; 



