. The crustacea of the plankton, July, 1894-Dec., 1896 . Fig. 7.—Leading Crustacea, 1894. Scale, 1 space = 100,000 Crustaceaper sq. meter. See p. 308. D. hyalina §m m ..9. Cyclops Fig. 10.—Total Crustacea, July-Dec, after deducting Chydorus. Scale, 1 vertical space = 100,000 Crustacea per sq. meter. See p. 312. a 9 - » ^ The Annual Distribution of the Crustacea. 3ia ing the same months, those individuals of Daphnia retrocurvadisappear, which have survived the reproductive period. Diap-tomus begins its decline in September or ea
. The crustacea of the plankton, July, 1894-Dec., 1896 . Fig. 7.—Leading Crustacea, 1894. Scale, 1 space = 100,000 Crustaceaper sq. meter. See p. 308. D. hyalina §m m ..9. Cyclops Fig. 10.—Total Crustacea, July-Dec, after deducting Chydorus. Scale, 1 vertical space = 100,000 Crustacea per sq. meter. See p. 312. a 9 - » ^ The Annual Distribution of the Crustacea. 3ia ing the same months, those individuals of Daphnia retrocurvadisappear, which have survived the reproductive period. Diap-tomus begins its decline in September or early October, andseems to make no special provision for winter forms. Cyclopscontinues its reproductive activity through the year, at least inperiods when the temperature of the lake is above 2° C, butwith a rate of multiplication declining as the temperature fallsbelow 15°. Larval Copepods are present in great numbers atall seasons, but their development into later stages is checked inwinter. Chy dorus seems to have the same habit as Cyclops; but,for causes as yet unknown, it almost disappeared in the wintersof 1894-5, 1896-7, although abundant in the preceding autumnsrand present in co
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