1893. | NEW YORK ACADEMY OF SCIENCES. 73 
suecess in hatching the means then suggested was water sterili- 
zation, the fungus spores to be removed by use of either filters 
or heat. 
The effect upon fungus growth of more perfect aération and 
increased salinity of water, however, had not been positively 
determined. And in the following experiment the writer aimed 
to reconsider these matters, hoping that favorable results might 
suggest a simpler and less costly means of evading fungus 
growth. 
The results of Prof. Ryder had been obtained in a small 
fresh water pond emptying through the river bank directly into 
the Delaware; the hatching cases had been placed in a sluice- 
way through which water was constantly escaping ; yet in spite 
of this current fungus inroads had here destroyed all but a few 
of the fertilized eggs. It was the plan of the writer to array a 
line of hatching cases from this shore point near the mark of 
low water out as far as the edge of the channel in deep water. 
By this means (the cases to contain eggs in every way similarly 
conditioned) the effects of difference of salinity, aération and 
silt deposit upon fungus growth seemed most likely to be under- 
stood. Surface waters of mid stream, stronger in current, 
would naturally be better aérated and more devoid of silt than 
marginal waters. In channel, moreover, the water density was 
noted at 1.007 (sp. gr.). 
The success of the experiment seems clearly to indicate the 
means that may be here taken to obtain practical results. The 
eggs in strong current, in salter and less silty waters, were prac- 
tically exempt from attacks of fungus; those in marginal waters 
speedily perished (see accompanying table). It would in fact 
seem to the writer that the fungus is rather a consequent than a 
prime cause of egg Geshruction That it is lacking under the 
natural conditions of sturgeon hatching is a fact not the most 
remarkable, and that it may be obviated in artificial processes 
by imitation of the natural hatching conditions seems the sim- 
plest and wisest plan of cultural procedure. 
NUMBER OF LOCATION. PERCENTAGE OF Ecos DESTROYED BY 
CASE. FUNGUS. 
2d Day. 3d Day. 4th Day. 5th Day. 
J. At outlet of fresh pond, 
as in experiments of 
Erol syder,.. ss choi 2a, BOO 
II. At stake near line of 
howy waters 3! 5 \.i./.'¢ Sae00 100 
