274 
BULLETIN OP THE UNITED STATES FISH COMMISSION. 
of the fact would seem to find some confirmation in the circumstance that many feral 
mammals when placed in confinement refuse to breed and become practically sterile. 
Judging from the number of live spawning fishes brought into Delaware City, Port 
Penn, and other places on the Delaware, there is but little doubt that several millions 
of ova for hatching purposes might be obtained each season by vigorous and faithful 
exploitation of all the sources of supply. To get the eggs will require that spawn- 
takers be distributed to each of the principal points where the caviare is packed and 
to closely watch the character of the fish as they come in and to immediately take the 
spawn in pans. If no mature or milting males are at hand the eggs are, of course, of 
no value. 
Owing to the great size and weight of the fish, taking the spawn from them directly 
in the sturgeon boats of the gillers will be found impracticable, since there would be 
too little room in which to work comfortably; besides, the fishermen would object to 
having their boats littered with the adhesive eggs, which stick to everything with 
which they come in contact. 
Penusgrove, Port Penn, and perhaps other points besides Delaware City, will be 
good points to operate, provided the water is not too brackish, which is greatly de- 
pendent upon the season, the river, as remarked before, being fresh much farther 
south during one season than during another. 
Important aid has been promised the agents of the U. S. Fish Commission by the 
State commissioner of New Jersey, and I have found that intelligent fishermen and 
caviare packers were also very ready to lend valuable assistance at Delaware City. 
Amongst those at the latter place to whom I have been under great personal obliga- 
tions I must not omit to mention Mr. Eeuben Anderson. 
14. METHODS OF STERILIZING THE WATER USED Ilf HATCHING THE STURGEON. 
Our experience with adhesive eggs of all kinds has always shown that it is diffi- 
cult to prevent the lodgment and rapidly fatal germination of the spores of Sapro- 
legnia or Adilya^ genera of fungi or moulds, found in all fresh waters upon dead as 
well as living fish eggs, and the rapid and fatal spread of the mycelium from affected 
to unaffected ova. So rapidly does this fungus grow that in a very short time its 
ravages will extend over an entire tray of adhesive eggs, so that in the course of four 
or five days the whole lot will be found to be covered with a mycelium, which by that 
time has not only passed into the fruiting or spore-producing stage, but has completed 
its work of destruction. 
The eggs are destroyed by the fungus sending filaments into their substance, 
while the mesh of the mycelium also affords lodgment for dirt, so that the two 
together effectually shut off the possibility of oxygenating the ova, so that they are 
smothered. The ova so affected are finally appropriated as nutriment by the fungus, 
which rapidly produces its spores or germs in vast myriads, only to pollute the water 
still more plentifully with its destructive germs. 
How to prevent the inroads of this pest is a matter of the very highest impor- 
tance, since upon the successful solution of this difficulty depends the success or failure 
of the artificial propagation of the sturgeon from artificially fertilized ova. 
My experience with eggs of the sturgeon at Delaware City proved that they were 
particularly subject to the destructive attacks of this type of fungus, and that unless 
