BULLETIN OF THE UNITED STATES FISH COMMISSION. 191 



ing approaches, instead of allowing the water from the hatching jars to 

 pass directly into the sinks, it is necessary to conduct it through the 

 collecting jar. This is precisely similar in construction to the hatching' 

 jar. Indeed it is the hatching jar with some special arrangements to 

 adapt it to its new purpose. The water passes from the hatching jar 

 through the rubber tube into the eccentric opening of the receiving jar. 

 The tube and opening then serve for the inlet instead of the outlet of 

 the water. On the lower end of the central tube is placed a wire frame, 

 over which is drawn a bag made of cheap cotton, the texture of which 

 is such as to permit the water to strain through, but the meshes of which 

 are so fine that the suction of the water will not hold the young fry 

 against it as would be the case if a wire screen were used. 



The surface of this strainer should be as large as is convenient. It 

 is adjusted to the lower end of the central tube in such position that 

 the end of the tube is in the center of the wire cage, or as nearly so as pos- 

 sible, the object of this being to make the draw of the water equal in 

 all directions. The water is allowed to pass out of this second receiv- 

 ing jar out into the waste. The young fish, if they be whitefish or shad, 

 as soon as they burst their shells begin to swim around vigorously in 

 the hatching jar, drifting with the current. They pass into the exit 

 tube and are carried over into the receiver, in which they may be col- 

 lected to any number desired, being retained there without injury until 

 it is convenient to make a shipment. 



In extensive work in hatching I have found it more convenient to 

 make use of large glass aquaria for receivers, four or five hatching jars 

 being disposed around one, which serves as a common collector for the 

 young fish from all. A siphon, arranged as shown in Fig. 4, with a 

 wire cage and strainer on the shorter end, serves to give free discharge 

 to the water while the strainer prevents any fish from passing out. 

 I have found the hatching jars tojbe a very compact form of apparatus 

 for handling the eggs of the salmonidse. In this case it is not desired 

 to nor do we give any motion to the eggs. The jar is filled with them 

 from one-half to two- thirds full. The current of water being introduced 

 at the bottom filters up through them, enveloping each egg in a stratum 

 of fresh water, and placing each under the best possible conditions of 

 development. From fifteen to eighteen thousand eggs may be readily 

 placed in each jar. Of course, in the case of these eggs we must have 

 recourse to hand-picking. This is readily accomplished by opening the 

 jars, placing the hand over the mouth to prevent the escape of water, 

 inverting and placing the mouth under water over a broad shallow tray. 

 The eggs by gravity flow out and spread over the bottom of this, and 

 when picked over are returned to the jar, the precaution being observed 

 to have the jar full of water, and to use a broad flat funnel to return 

 the eggs. They may be poured from the tray into the jar in bulk with- 

 out any injury. 



From the experience had during the winter of 1882 in hatching this 



