[13] FISHERIES OF THE UNITED STATES. 1167 



yet been invented for floating eggs that proves entirely satisfactory, 

 though several forms are used with fair results. These are the floating 

 box, arranged to utilize the action of the waves, a cylindrical hatching- 

 can, made to revolve by means of machinery, and a modified form of the 

 Clark hatching-trough. 



Formerly, the work of any fish -cultural establishment was limited 

 to the quantity of eggs obtained in the immediate vicinity, which were 

 usually secured from fish kept in the ponds of the hatchery, or from 

 those taken in the adjacent river. Later, boats were employed to ena- 

 ble the spawn-takers to go out among the net-fishermen, and, later still, 

 steam-launches were introduced to enable them to visit more distant 

 localities. Another plan, which has considerably reduced the expense 

 of artificial propagation, has been the building of floating hatcheries, 

 which can be towed to any given locality, and after the spawning sea- 

 son is over these can again be taken in tow and carried to a more north- 

 ern fishing center to continue the work ; thus the same hatchery and 

 equipment can be employed in hatching eggs of the shad in Florida 

 waters in January and February, on the Carolina coast in March and 

 April, in the rivers of Maryland in May and June, and on the New Eng- 

 land coast later in the season. 



Within the past few years satisfactory experiments have been made 

 in securing eggs and shipping them either by rail or steamer to hatch- 

 ing stations quite remote from the fishing grounds. This plan has long 

 been applied to the eggs of certain species of Salmonidcc, but it is only 

 recently that it has been employed with the eggs of the shad. Men are 

 now sent with a camping and collecting outfit to the different fishing 

 stations along the river banks, with rations to last them during the 

 fishing season, their duty being to examine the fish at each haul of the 

 seine, secure such eggs as may be obtained, and put them on board the 

 river steamer for shipment to the hatching station. In this way the 

 expense of the work has been greatly reduced. Another plan of 

 increasing the quantity of eggs for any particular hatchery is to 

 build pens capable of holding considerable numbers of fish. For some 

 years the practice of the U. S. Fish Commission was to visit the nets 

 of the fishermen and take the eggs from such females as chanced 

 to be in proper condition, a very large proportion of the fish be- 

 ing either spent or too immature to enable the eggs to be impreg- 

 nated. Numbers of eggs were lost in this way, and it was found expe- 

 dient to collect the fish and pen them until they should ripen, when the 

 eggs could be secured. Different plans are adopted to accomplish this 

 purpose. At Grand Lake Stream, where the land-locked salmon are 

 hatched, net basins are constructed along the bank and netting is 

 stretched across the stream when the salmon ascend to spawn. These 

 nets or wings turn them into the basins, where they are retained until 

 the spawning season arrives, when they can be examined from day to 

 day and all the ripe eggs secured. In California the same end is ac- 



