244 BULLETIN OP THE UNITED STATES FISH COMMISSION. 



sbaimy, Yarrell's blenny, viviparous blenny, 3-spined stickleback, bib, green cod, 

 pollack, the rockliugs, halibut, turbot, Miiller's topknot, salmon, gar-pike (ovarian), 

 minnow, conger (ovarian), twaite-sbad (ovarian). Further information lias been gained 

 about eggs which bad been batched elsewhere, such as the lesser weever, rockling 

 (Motella mustela), little sole, herring, and others, besides the young of various skates, 

 dogfishes, and the viviparous blenny. 



Besides the study of the living eggs, larva 1 , and young fishes, large collections of 

 preserved pelagic ova, larva), and young fishes have for several years received special 

 attention. They are made by the Garland, the ship used by the Scotch Fishery Board 

 for scientific observations, according to special instructions, and the ova are preserved 

 in 4 parts alcohol, 4 parts acetic acid (2 per cent), and 1 part camphor, after being 

 killed in a saturated solution of picric acid in 5 per cent hydrochloric; acid; the larvae 

 and young fishes are killed by a saturated solution of corrosive sublimate, washed, and 

 then placed in methylated spirit, and changed if many are in one tube or bottle. By 

 careful study and comparison the nature of many of the ova can be made out, and 

 the numbers Of each in the respective areas determined. The nets of course, are kept 

 down for a fixed period, and both surface and bottom nets are used simultaneously. 

 By summing up the results of the trawl and of the contents of the tow nets, the con- 

 dition of the several areas in regard to food and other fishes is determined with consid- 

 erable accuracy, while the occurrence and distribution of ova are also observed. 



II.— ON THE HATCHING OF MARINE FISHES IN RELATION TO THE FISHERIES. 



Though from the foregoing remarks it will be seen that most of the important 

 food-fishes have been hatched at the St. Andrews Marine Laboratory, yet it can not 

 be said that in this country the hatching of such fishes has been carried out on a large 

 scale. The Fishery Board for Scotland have nearly completed an establishment of this 

 kind at Dunbar (see pp. 257-262), and fishes have been collected for next season, but no 

 actual hatching on a large scale has occurred. The importance of the issue demands 

 that a thorough trial be made, though it has not yet been proved that the artificial 

 hatching of sea fishes will be beneficial to the fisheries generally. Iu performing 

 experiments of this kind it is best to select a fish not only suitable and hardy, but 

 one comparatively rare in the vicinity of the hatchery, if not entirely foreign to the 

 area. The increase of such a fish after the operations can not thus be mistaken. For 

 example the sole (Solea vulgaris) has been selected as the best fitted for experiment 

 at Dunbar, since comparatively few exist in the neighborhood, and the larva) and 

 young are hardy. The same species has been chosen for experiments in transporting 

 the adults and adolescents into new areas, such as St. Andrews Bay, into which 

 several hundred were placed this autumn. The plaice (Platessa vulgaris) will also be 

 hatched at Dunbar. For experiments of the first-mentioned kind the fjords of Norway 

 are admirably adapted, since constant fishing has greatly thinned the native cod (a 

 small variety). If, therefore, Oapt. Dannevig can show that his millions of larvae, 

 which for some years have been sent into the water, have had the effect of increasing 

 the number of cod captured by the fishermen of the locality, a strong case will have 

 been made out. 



So far as we in this country can judge, the American experiments have not re- 

 sulted in anything very definite in regard to sea fishes. It is doubtful, however, if 

 the scale on which such experiments have been conducted has been sufficiently large 

 to merit confidence. Again, we are in want of accurate data to guide us in regard to 





