NCII REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
the milt may be extracted by pressure, and while Prof. Ryder was not 
successful with the milt obtained in this maimer on two occasions, he 
thinks the eggs themselves may have been at fault and advises further 
experiments in this direction. In Germany this method has given good 
results. 
The course to be pursued in the handling of the eggs is described by 
Prof. Ryder as follows : 
Not more than twenty minutes should he allowed to elapse after the time the 
milt and eggs are mixed together till they are spread upon cheese-cloth trays, one 
egg deep, or in a single layer. If this is not done immediately the eggs will stick 
together in large masses, causing those at the center of these masses to he asphyxiated 
for want of oxygen, which under such circumstances can not find access to them. 
* * * It is, therefore, very important that a large number of trays properly 
constructed he at hand upon which to spread the eggs if any extensive hatching 
operations are to he conducted. The eggs will adhere very firmly to the surface of 
the cheese cloth in a few hours, after which further watchfulness is necessary in 
order to keep down any fungus which may appear upon the dead eggs, of which 
there will always he some. It may be possible that panes of glass would serve the 
same purpose as the cheese-cloth trays if a current of water were allowed to flow 
very slowly between a superimposed series of glass plates properly disposed in a 
trough. * * * Upon admixture with water the adhesive material with which 
the eggs are covered seems to be dissolved somewhat and becomes diffused through 
the water, so that the whole becomes ropy. * * * This glairy or ropy character 
of the partly dissolved coating of the egg persists for some time, usually for thirty 
minutes or so, after which time the glairy substance hardens or coagulates in the 
presence of the water and the gases held in solution by it. In process of hardening 
the glairy, sticky coating of the eggs firmly fastens them to whatever they are 
brought into contact with, and after that has occurred it is scarcely possible to 
detach them without injury to their delicate, thin envelopes and their soft, viscid 
contents. 
****#**■ 
The trays used at Delaware City, on board the steamer Fish Hawk, were made 
by tacking cheese cloth to light wooden frames a foot wide and 18 inches long; 
then loading the edges of the frames with strips of sheet lead to keep them im- 
mersed. These trays, placed on ledges in a superimposed series, in a trough through 
which the water is allowed to flow gently, is a very efficient hatching device. Float- 
ing hatching-boxes with brass-wire gauze bottoms and small openings at the sides 
covered with the same kind of gauze have been successfully used by the Germans, 
one having been brought from Germany by Mr. S. Feddersen, of Port Penn, Del., 
from Hamburg. The floating box in which the writer succeeded in hatching out 
a batch of the eggs of the sturgeon was exceedingly simple in construction, and 
consisted of a soap box with tdp and bottom removed, the bottom for which was 
then replaced by tacking cheese cloth to the lower edge of the rim, and by nailing 
wooden strips to serve as floats to the sides of the box a very efficient hatching- 
device was extemporized. These boxes so modified were placed at the edge of the 
large fresh-water pool near the extreme eastern end of the Chesapeake and Delaware 
Canal, at a point where there was a constant flow of fresh water under them. The 
only lot of fertilized eggs which the writer succeeded in obtaining were spread on 
the bottoms of these boxes and left to hatch. In six days from the time of fertiliza- 
tion the young fish made their appearance. The rapid appearance of a parasitic 
fresh- water fungus, however, caused such extensive mortality amongst the eggs that 
very few embryos survived to escape from the egg membranes. This fungus, which 
appeared to be a Saprolegnia, is developed from spores which seem to be almost every- 
where present in fresh water. 
