[19] PROPAGATION OF WHITEFISH AT NORTHVILLE, MICH. 572 
hourly changes of water. The trays were then removed to a cellar, 
where they remained until November 26, when they were brought on to 
the hatchery via Sandusky, arriving the next day at ll a.m. Eggs 
looked well when received, but some doubts as to results were felt, no 
record of the temperature to which they had been exposed while in the 
cellar having been made. They were placed in two of the Chase jars, 
and watched with considerable interest. The percentage of loss was no 
greater than the average, and the fish began hatching at precisely the 
same time as other eggs of the sameage. The length of time that white- 
fish eggs of this age may be retained on trays without material injury 
has not been fully determined, and experiments in this direction, as well 
as others in regard to their treatment at this, their most critical period, 
were intended to have been made, after having secured the complement 
of eggs for the hatchery, but the season terminated abruptly and before 
the desired numbers had been obtained. 
The regular employes of the hatchery at this time were Mr. I. Slaght, 
Mr. A. W. Root, and Mr. S. Bower, and the respective duties assigned 
to each were well performed. Mr. Slaght was given the immediate 
supervision of the eggs in the hatching-boxes; Mr. Root was employed 
as carpenter and general assistant ; and Mr. Bower was intrusted with 
the immediate care of the eggs in the jars, and also attended the office 
work. 
The principal and most important of the work of the latching-room 
from this time on, consisted in protecting the live eggs from the fatal 
presence of the dead egg of confervoid growth, and from the per- 
nicious influences of slimy coatings and sediments. Other general work 
included a periodical cleaning of the tanks, troughs, trays, hatching- 
boxes and flannel screens, to remove slimy deposits and accumulations; 
making shipping cases and shipments of eggs; the construction and 
operation of a refrigerator; confining the temperaturé of the water to 
certain limits by the use of ice and snow when necessary; repairing old 
and constructing new tanks, and fitting them for the reception of the 
fry; and finally the general distribution of the young fishes. 
In the artificial propagation of whitefish, if the eggs have been taken 
with a greater regard for quality than quantity, and are given special , 
care and attention under favorable circumstances until received at the 
hatchery, 85 to 95 per cent. may be hatched. If the eggs have been 
secured under the conditions just indicated, nearly accurate calculations 
as to the number of young fishes to be shown at the end of the season 
can then be made; results can be anticipated with confidence. But ap- 
proximate estimates cannot always be made from the appearance of the 
eggs on arrival at the hatchery, their aspect at this time generally giv- 
ing no clew upon which to base computations, as the fruits of prior 
neglect: or defective treatment may not yet be apparent; neither does 
the unimpregnated egg exhibit any distinguishing marks visible to the 
unaided eye, by which its presence may be detected. The lapse of a 
