[5] EGGS OP THE PLAICE, FLOUKDEE, AND COD. 431 



fish closely resembled the herring. The intestinal canal, back of the 

 stomach, however, takes a somewhat different and more crooked course. 

 They also somewhat resemble the small fish called by Agassiz Osmerus 

 mordax. 'Sothmg is said, however, about the construction of the chorda 

 in this last-mentioned fish. Both the herring and the Osmerus have 

 bubbly yolk, and therefore differ very noticeably from the fish ob- 

 served hy me. In 1882 I caught large numbers of eggs, whose yolks 

 had a broken appearance, near the Diinenkathe, opposite Friedrichsort, 

 and between Jiigersberg and Korugen, therefore near the mouth of the 

 bay. All the fish mentioned so far did not have red blood, prior to the 

 absorption of the yolk. 



Other eggs observed by me were those of the Cottus scorpio, which 

 adhered to piles in the bay in large numbers (during January to April), 

 and of Cyclopterus lumpus (April). These last-mentioned eggs Professor 

 Mobius obtained from Eckernforde, where they were found adhering to 

 a pile in such a large lump as to render it improbable that they were 

 laid by one fish. The eggs of the Cottus showed numerous protuber- 

 ances and measured 1.4 millimeters, whilst the young fish measured 5.4 

 millimeters. The eggs of both these fish contain drops of fat, which, 

 especially in those of the Cyclopterus, are very large and almost color- 

 less. The young of both these kinds of fish, when leaving the egg, 

 show a complete circulation of red blood, and are exceedingly lively and 

 well developed. The Cottus forms a beautiful object under the micro- 

 scope, whilst the Cyclopterus is opaque, with a thick-set body and a 

 small tail. The suction disk makes its appearance a few days after the 

 fish are hatched, and is put to frequent use. The protuberances on the 

 head "and dorsal fin do not develop until the yolk has been absorbed, 

 i^umerous older specimens of Cyclopterus were, in May, found among 

 the sea- weeds outside of the bay. In both these fish the chorda has 

 several rays, and the sphincter is close to the yolk. The only fish 

 whose sphincter was midway between the yolk and the end of the tail 

 (similar to the Ctenolabrus cccruleus* according to Agassiz) was a small 

 Oobius, whose eggs were found adhering to sea-weeds. 



The object in view, to find spawn of the plaice and the flounder dis- 

 charged in a natural way, seemed to be attained. The eggs were found 

 scattered and lying loosely on the bottom in deep places of the sea near 

 the coast, in places where plaice fisheries were carried on. This agreed 

 with Malm's statement, that the impregnated eggs gradually sink to 

 the bottom, but not with Agassiz's statement, that he had found eggs 

 of flat-fish {Pseudorhombus ohlongus Stein) floating about near the surface. 

 Strictly speaking, the object in view could only be considered as at- 

 tained so far as the year 1881 was concerned, as became evident later 



* C. Sundetcall: "Om Fiskyngels utveckliug." Kgl. Svenska Vetensk. Akad. 

 Handliuger, N. P., Vol. I, 1855, gives drawings of young fresh- water fish, according 

 to wliicli the sphincter occupies a position in the middle in Perca, Esox (very far 

 back), Cyprinu8 rutilus and idua. 



