22 U. S. BUREAU OF FISHERIES 
The lowest of the tiers of boards that form the sides and ends of a 
box are nailed close against the bottom, but a 1-inch space is left 
between the remaining boards. In a stream that has an appreciable 
current it is advisable to cover the sides and ends of the boxes with 
wire cloth five meshes to the inch to prevent the eggs being washed 
through the openings. 
Duri ing flood in many rivers and streams strings of yellow-perch 
eggs may be found suspended from sticks and bushes along the 
banks. As the waters recede the eggs are exposed to the elements 
and soon die. Large quantities of eggs are collected annually from 
such places 1 in the Missisquoi River in Vermont and are incubated in 
the bureau’s Swanton (Vt.) hatchery. 
At the Bryans Point (Md.) hatchery on the Potomac River and at 
some other stations of the bureau where the propagation of yellow 
perch is conducted two methods are employed in developing the eggs, 
the one in more general use being to incubate them in jars similar to 
those used in the hatching of w vhitefish eggs. Owing to the great 
tendency of yellow-perch eggs to swell, and to their lightness as com- 
pared with the eggs of shad or W hitefish, it has been found advisable 
to apportion them in jars at the rate of only about 2 quarts to a jar. 
In some instances a wire screeh of fine mesh is placed in the overflow 
of the jars. Great care must be exercised in regulating the flow of 
water in the jars, as the current caused by too much water will force 
the eggs to the top, where they will either clog the outlet screen or, 
in the absence of a screen, will pass out into the fry trough. 
At several of the hatcheries wire hatching baskets suspended in 
a neighboring river or stream, are successfully used for the incuba- 
tion of yellow -perch eggs. These baskets are cylindrical, about 15 
inches in diameter and 20 inches long. They are made of fine-mesh 
wire cloth and are provided with a hinged door having a catch or 
lock, to guard against loss of eggs duri ing incubation. About 3 
quarts of eggs are “placed i in each basket, the door is fastened, and the 
basket is suspended in the water by means of floats or stakes. 
A simple float, in a stream that is subject to sudden changes in 
water level, is made of a 2-inch plank, 12 inches wide and from 10 
to 12 feet long, into which nails have been driven alternately at 
intervals of 1 foot on each side. After tying the baskets to the nails 
the plank is anchored in a suitable spot ‘where there is no danger of 
the baskets touching the bottom. The apparatus should be inspected 
by an attendant at least once a day, and each basket gently raised 
and lowered several times to free the eggs from adhering sediment. 
PIKES 
DESCRIPTION 
The muskellunge, pike, and pickerels are all pikes in a generic 
sense. There are other fishes belonging to entirely different families 
and, therefore, structurally different and distinct from the true 
pikes, which, ‘unfortunately, have the local names of pike and 
pickerel. The most common species thus designated belong to the 
perch family. The spinous dorsal fin possessed by these fishes 
readily distinguishes them from the true pikes. They are more 
properly designated as pike perch, wall-eyed pike, sauger, etc. The 
