. The crustacea of the plankton, July, 1894-Dec., 1896 . CD i—iCO CO o CO © 02 02 J-f<DPh 0303 a 02P O oo oo o ft 02 o <3 OSCO S3 ac3 -4-3 02 P uo be a c3 CO 6 a r—I d ft I O I XX —? 5 x o £ HH m P »-3. 8 The Annual Distribution of the Crustacea. 309 on their development. At the time of the maximum Cyclopsmay number more than 2,500,000 per sq. m. of surface, but ofthis enormous number only a very small fraction ever becomesexually mature. In any catch made at this season of the year,not more than five per cent, are mature, and not more than oneor two per cent, are egg-bearing females. Th
. The crustacea of the plankton, July, 1894-Dec., 1896 . CD i—iCO CO o CO © 02 02 J-f<DPh 0303 a 02P O oo oo o ft 02 o <3 OSCO S3 ac3 -4-3 02 P uo be a c3 CO 6 a r—I d ft I O I XX —? 5 x o £ HH m P »-3. 8 The Annual Distribution of the Crustacea. 309 on their development. At the time of the maximum Cyclopsmay number more than 2,500,000 per sq. m. of surface, but ofthis enormous number only a very small fraction ever becomesexually mature. In any catch made at this season of the year,not more than five per cent, are mature, and not more than oneor two per cent, are egg-bearing females. The great majority,therefore, of these Cyclops die without reaching maturity, andafter the maximum has been passed the number of Cyclops de-creases even more rapidly than it rose. The decline may go sofar that in June the number of this species is scarcely largerthan in March. During this decline of Cyclops, the other perennial species areincreasing in number, but their combined increase is morethan counterbalanced by the decrease in the number of Cyclops,so that the late spring and early summer show a marked declinein the total number of Crustacea. The Crustacea in Summer. The summer life of the Crusta
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