554 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. 



" They escape through the meshes of the wire-cloth as fast as they 

 hatch. It will take at least tweuty-foiir wires to the inch to hold them, 

 aud I think the eggs require less current than shad-spawn. 

 "Yours, 



MAEOELLUS G. HOLTOK 

 " Prof. Spencer F. Baird, 



" Washington, D. C." 



Mr. Holtou, in another letter, reported the eggs obtained from two 

 spawners at 120,000, and out of these he estimated the number hatched 

 at about 70 per cent., or 80,000 young fry. The female parents weighed 

 six and eight pounds. The eggs were nearly equal in size to those of a 

 shad; the newly-hatched fry were somewhat smaller. 



The fact that the ova were non-adhesive, unlike most of the percoid 

 fishes that have been dealt with, was a matter of surprise. The weight of 

 the spawning-fish is somewhat less than has usually been attributed to 

 rock-fish in spawning-condition. If localities can be found where rock- 

 fish may be taken in sufficient numbers in the breeding-season, the 

 increase of this species is lirobably as sure to be effected as that of the 

 shad has been. 



We append a list of the species already referred to, and also of those 

 with which small experiments have been made, with varying success, 

 in the United States. The perch, {Ferca flavescens ;) the wall-eyed 

 or glass-eyed pike, {Stizostedium americammi ;) the rock-bass, {Boceus 

 lineatus ;) the salmon, {Sahiio solar ;) the California salmon, {Salmo 

 qiiinnat ;) the hvodk-tvoxit, [Salmo fontinalis ;) the Pacific coast brook- 

 trout, (yiSa/wo iridea ;) the Utah trout, {Salmo virginalis ;) the land- 

 locked salmon, [Salmo sehago ;) the salmon or Mackinaw trout, [Salmo 

 namaycnsJi ;) the lake white-fish, [Coregonus alhus ;) the Otsego bass, 

 [Coregonus otscgo ;) the lake-herring, [Coregonus clupeiformis ;) the gray- 

 ling, [Thymallus tricolor ^) the shad, [Alosa sapidissima ;) the alewife. 

 [Pomolobiis pseudo-harengus ;) the common sucker, [Catostomus com- 

 munis ;) the shiner, [Stilbe crysoleucus ;) the corporal or chub,( Semotilus 

 corporalis.) 



Collating from numerous authorities on fish-culture in Europe, we are 

 enabled to give the following list : The burbot or la lotte, [Lota vulgaris ;) 

 the salmon, [Salmo salar ;) the sea-trout, [Salmo trutta ;) the river- trout, 

 [Salmo far io) ; the lake-trout, [Salmo lacustris ;) the omhre chevalier or 

 rothel, [Salmo umbla ;) the charr, [Salmo alpinus ;) the hucho, [Salmo 

 hucho ;) the laveret, [Coregonus laveratus ;) the tera., [Coregonus fera;) 

 the msbYsen-<i, [Coregonus marama ;) the j)alee, [Coregonus palea ; the Core- 

 gonus albtila ;) the grsiyMng, [Thymallus vulgaris ;) the e?kV]}, [Cyprinus 

 carpio ;) the crucian carp, [Cyprinus carassius ; Cyprinus Iwlfarii ;) 

 the tench, [Tinea vulgaris;) the white-bream, (A&mm is blicca ;) the 

 ablette, [Cyprinus alhurnus ;) and the sterlst, [Acipender ruthenus.) 



Of the hybrids claimed to have been produced artificially, which but 

 few seem to have attained maturity, we give the following list : 



