74 TRANSACTIONS OF THE [Nov. 13, 
NUMBER OF LOCATION. PERCENTAGE OF EaGs DESTROYED BY 
CASE. FUNGUS. 
2a Day. 3d Day. 4th Day. 5th Day. 
III. At wharf sluice, a rod 
further out; :.. . <5. 20 80 100 
IV. At wharf end, a ‘tod fe 
THErOUL,....% eriekess 0 20 50 60 
V. In deep water in current 
at break water,...... 0 5 5 i) 
It would appear from the above results that the problem of 
i eae sturgeon eggs is intimately conditioned by water cur- 
rent, by silt deposits, by salinity of water. To determine to 
what degree each of these factors is contributive to success would 
be granted most difficult. In the particular case of the common 
anadromous sturgeon (4. sfurio) a slight degree of brackishness 
of water might be regarded as a favorable, if not a necesssary 
condition, were it not that the eggs of this species have been re- 
peatedly hatched in water absolutely fresh. Current, on the other 
hand, could not have been alone an essential condition ; since in 
the fresh sluice-way at Delaware City in the experiments of Prof. 
Ryder a circulation maintained stronger undoubtedly than in 
channel waters. Nor could the effect of silt be regarded as alone 
the unfavorable element; quantitatively in mid-stream—espe- 
cially in sturgeon waters—an amount of sediment might be 
expected greater, doubtless, than of a neighboring spring-fed 
pond. Mode of temperature variations might, again, be looked 
upon as of problematic value. To what degree, then, is each of 
these conditions to be regarded as essential for success in stur- 
geon hatching? This problem, it cannot be doubted, is more 
troublesome in theory than in practice. 
As to obtaining simultaneously the spawning fishes, male and 
female. In the event of extensive culture this difficulty is one 
that in the opinion of the writer could not be regarded as of 
serious weight. In a favorable locality each season brings a 
number of spawners to the wharfs of the fishermen, and with a 
regularity of occurrence that appears remarkable. Ina letter to 
the writer Mr. Reuben Anderson, of Delaware City, well known 
as a most careful observer of the habits of the sturgeon, pre- 
dicted to a day the appearance of spawners. He afterward stated 
that the “run” of fish,* though brief—often not longer than a 
x A breeding habit of the stur¢ eeon Mr. Anderson discussed with the writer 
seems for cultural purposes of the utmost significance The earliest fish in 
their passage up the stream spawn furthest from the river mouth, the next 
school ina locality not as distant, and the later fish in the lower stream regions. 
This zonal distribution in spawning seems attested by the character of fish as 
taken in their journey past a single shore front; the earliest are uniformly 
“cavaire fish” (i. e. of immature ovaries) ; later are taken “runners? acces, 
ripe fish); and at the close of the spawning season none but “slunkers”’ (i. e. 
those having spawned). 
