■'450 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [24] 



natecl ? The eggs vrliicli have not been impregnated may remain floating 

 ■for several days. It would, therefore, be necessary, for obtaining toler- 

 ably correct average figures, to gather the eggs above the spawning 

 fish, and determine the percentage of eggs which have not beeu im- 

 pregnated, by taking them from the water in the most careful manuer. 

 The question can only be decided if the eggs can be kept alive for about 

 ' 24 hours, which is only possible by taking ice along in the boat. In 

 5 boats which are not constructed in such a manuer as to allow of micro- 

 :scopic observations on board, this is recommeuded under all circum- 

 ■ stances, for below deck the water soon becomes warm, and ou deck it 

 is diffi(;ult to protect the glass vessels against the suu, as the vessel 

 'Often changes her course, and as the attention of the scientist is required 

 liu other directions. 



We furthermore ask. How many of the eggs die prematurely f With 

 regard to this question I feel justified to state that their number is, on 

 the whole, not very large. Dead eggs, as 1 have found by direct obser- 

 vations in the aquarium, will very well keep from 8 to 14 days. If, there- 

 fore, there had been any, I must have caught some with the bottom-net. 

 It is true that I brought up a certain number of such eggs — every catch 

 yielding one or two, and on the 27th of April I even got — near Buoy No. 

 1 — 1() dead eggs along with 50 live ones, the average distribution being 

 1.8 egg per square meter of the bottom ; but here the spawning period 

 was over, and a large number of eggs had probably accumulated owing 

 to this fact. Finally, the exceedingly difficult question remains to be 

 answered — how many eggs are devoured by various marine animals. 

 The dangers which arise, when the eggs touch the bottom, have already 

 been mentioned. 



The Entomostracans do not seem to hurt the eggs. I am, of course, 

 not absolutely certain on this point, as eggs which had been bitten 

 would run out; aud as it requires special observations to ascertain 

 whether egg-shells are found which are sinking or about to sink. The 

 aumber of small crustaceans is frequently so great that the eggs must 

 ■be entirely annihilated if these animals were among their enemies. I 

 tiave also often, in the large aquarium of the commission, observed 

 •eggs floating among the crustaceans, and never could 1 find that they 

 were in the least molested by them. 



Fish are hardly dangerous to the scattered eggs, for on account of 

 their great transperency they are, when occurring singly, hardly per- 

 ceptible, nor would it pay the fish to hunt for them. Sars says: "It 

 seems that not only other marine animals, but even the codfish them- 

 selves, when they return to the high sea, destroy a large number of the 

 eggs which fill the ocean." Although the fact does not seem to be posi- 

 tively proved by this statement, it seems certain that, wherever the 

 eggs occur in very dense masses, they are devoured by fish. No esti- 

 mate as to the quantity of eggs destroyed in this manner could be 

 ^•ained, unless one could be directly over the spawning masses offish. 



