[17] 



EGGS OF THE PLAICE, FLOUNDER, AND COD. 



443 



net was closed and thus let down to the bottom, and hauled up thence. 

 Its opening was 0.1182 square meters. The result of my observations 

 was as follows: 



Location. 



Observations. 



Off Danen-Ratheu . 



Buoy No. 1 in the open sea. 

 about 19 kilometers from 

 Kiel. 



4 kilometers farther north- 

 east. 



4 kilometers farther . 



Buoy No. 2 ; 15 kilometers 

 from Kiel. 



Stoller-Grund ; 21 kilome- 

 ters from Kiel ; 7 kilome- 

 ters from Bilk . 



5 kilometers from the Stol- 

 ler-Grund beacon ; 12 kil- 

 ometers from Bilk. 



21 kilometers north of Bilk . 

 25 kilometers north of Bilk . 



28 kilometers north of 

 Bilk ; Aaro in view. 



5 kilometers north of Bilk. 

 Buoy No. 1 



April 7, 1883 : 11 hours from Kiel ; weather very fine, 

 sea calm ; .specific gravity 1.0158 at3.8° (at 17.5° = 1.0- 

 142 sp. g. =1.86 per cent, salt): drew surface-net 96 

 meters; many diatoms, some Sargi^; the diatoms al- 

 most exclusively Chdtoeerot, Sarsia tubuloea, and occa- 

 sionallv Dysmorphosa /ulgurans. — No eggs. 



Sp. g. 1.0157, at 2.7^ (at 17.5° = 1.0142 sp. g.) surface-net 

 96 meters: diatoms; 420 eggs, among them 19 small 

 ones ; and amonfj these 3 with drops of fat 



Bottom-net on red alga; 96 meters; 23 eggs ; among 

 these 1 codfish egg, 19 plaice eggs, and 3 flounder eggs. 



Bottom net; s;indy bottom 50 meters; 44 eggs; among 

 these 16 small ones; 28 plaice eggs and codfish eggs. .. 



Surface ti.Hhtd for 96 meters; many diatoms; 2,399 eggs; 

 among these three with drops of fat (probably more), 

 and 6-t sniiiU eggs (floniuder.) " 



Bottom-net 99 meters, depth 10 fathoms; 33 large eggs, 

 which did no longer float ' 



Surface 96 meters ; no diatoms ; many entomostracans; 

 1,554 eggs; among these 19 with drops of fat; 65 

 flounders 



After sunset, the sea perfectly calm ; fish playing near 

 the surface. A great many diatoms; fished 180 me- 

 ters ; 6 eggs; 2 of these small ; all eggs caught this 

 day, young; no pigment in the eyes of any of the em- 

 byros. Back in Kiel at 10 p. m. 



April 13, 1883 ; lOJ hours from Kiel. East wind ; sea a 

 little rough. Sp. g. 1.0152 at 3.4°, at 17.5° 1.0138 sp. g. 

 = 1.81 percent. salt. Surface-net, 50 meters; diatoms; 

 53 eggs ; 3 small eggs and 50 cod and plaice eggs 



Verticalnet; depth 10 meters; hauled upnetonce; 2egg8. 



Bottom-net, 80 meters; stony bottom; 215 eggs: among 

 these 34 small eggs, 65 plaice eggs, and 1 spoiled egg. . 



Surface-net 96 meters ; diatoms ; 179 eggs ; among these 

 11 small ones 



Surface-net, kept at same depth, drawn 96 meters ; 35 

 eggs; among these 2 small ones; J egg per square 

 meter 



Vertical net, hauled 3 times at a depth of 13 meters; 36 

 eggs 



Bottom-net 96 meters ; 13 eggs ^ 



Surface-net 96 meters ; many diatoms ; 110 eggs 



Surface-net 96 meters ; hardly any diatoms; 1,121 eggs; 

 of these 124 small ones, and of these 60 with drops of 

 fat 



Bottom-net; many diatoms ; no eggs, it seems ; some of 



them, however, may have been overlooked 



Vertical net hauled 3 times, at a depth of 18 meters ; 31 



Sp. g. 1.0134, at 3.2° (at 17.5° =1.0120 sp. g. =1.54 per 

 cent. salt). Surface net 96 meters ; 3 eggs in the net, 

 which probably had been in it from the last haul; no 

 diatoms; manj' entomostracans. A strong current; 

 it evidently was met by water which, driven by the 

 east wind, was rapidly flowing from the Eastern Baltic 

 towards the Sound and the Belts. 



Sp. g. 1.0151 at 3.5° (at 17.5° 1.0135 sp. g.= 1.77 percent, 

 salt). Water rough ; surface-net 50 meters, 58 eggs; 

 no diatoms ; many Sarsia and entomostracans ... 



Same ; 21 eggs ; many eggs contained embryos which 

 were considerably developed ; back in Kiel at 9 p. m. . . 



5.5 

 0.6 

 1.2 



31.2 

 1 



20.1 



1.3 



17 



7 

 2.3 



101 

 0.4 

 1.4 



1.5 

 0.5 



6.04 



32.2 



20.1 



102 



84.5 



"The calculation per square meter is as follows: The surface-net of a breadth of 0.8 meters 

 drawn a distance of 96 meters, 0.8 = 76.8 square meters with (o. g.) 420 eggs, y^^?? :=5.5 eggs persquare 

 meter. The vertical net drawn 3 times corresponds to a surface of 3 x .01182 = 03546 square meters with 

 a haul (e. g.) of 36 eggs, ^-M^s = 101.5 eggs per square meter. Add to this eggs at the bottom, 0.4 per 

 square meter, and we get 102 eggs per square meter surface. 



