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Effect of temperature fluctuations on plankton.................... 474 
Invearly Spring Of 18o6s,..ccemmer eccrine hele rercteeiaens 475 
In‘late autumn Ob 1897: n-neneb serie tens ie Ten eeeeeere eee 476 
Exceptional high production at minimum temperatures.......... 476 
Effect of autumnal decline in temperatures....................-- 477 
Effect-of temporary heatipnlses seems eeereenct a cee cerita 477 
Eifectofithe winterice-Shee ter mcsvayaeeeeta tee tle -t te eteie etait 479 
Light.and plankton) prodte trombone crue ctetseaete re tte otek lanes otefoaeya ecole ete ot 480 
Imperfection ol datai.ii near water eb rastetie inie ois, ctelaiteneaieieee 480 
Production in periods of greater and less illumination.............. 480 
Production in clear and turbid waters................-2--ee000eeee 481 
Production in clear and cloudy weather.................-0222-000- 482 
Vegetation and plankton production................2.0.eeee cece eee 483 
Greater production in vegetation-poor lakes.................---+-- 484 
Comparison of monthly means of production in lakes rich and poor 
in. vepetationl s:<2 cis, pres beeen cis eo etleiescitamet eels ect le cele 484 
Seasonal changes in vegetation and in relative production....... 485 
Combination of other factors with vegetation to depress production 486 
Current and tributanyewateneyremmee eee etl cist ene eres eieree 487 
Chemical: conditionsea-.. seen ee ee ee ne oe 488 
Corroborative evidence from Matanzas Lake..................-. 489 
Production in Quiver and Dogfish lakes in years of much and little 
Vegetation ...i.% vc. meee seis te ekeer bik nictes eheiaeate erate eke 491 
Depression of production during dominance of submerged veg- 
CLACIOM 55 .5e cess wise ecelete alten ciate teeter eR reap Tai te det esate 493 
Production in vegetation-rich waters of Flag Lake............... 494 
Emergent vegetation a source of enrichment.................. 494 
Struggle for existence between submerged flora and phytoplank- 
POM 5 joe's boos Bd satis eyalonaca: eke Bae ave hf SanU TST RUPP nae eis lore eee ieracot 496 
Chemical conditions in the two types of lakes.................... 497 
Impoverishing effect of submerged vegetation.................. 499 
Obstructive effect of submerged vegetation...................-. 499 
Effect of vegetation on constitution of plankton........... ...... 500 
Effect of vegetation on fish production.......................-.- 501 
Experiment suggested...... Fobosenoodn Yaigwoh HO oocachbadoabpunes 6 502 
Internal factors and plankton production .................0--.02 20000 502 
Normal regimen of plankton production................-.0+2.+.0-000- 503 
No seasonal regularity in amplitude of production.................... 504 
Rank of different stations in production more stable...............-. 504 
Degrees of stability im different slocalitiess:-).- 1... <= +> <= 505 
Is there a normal sequence in production?............... ......0.0. 506 
Direction of movement in mean monthly production............... 507 
Predominant seasonal changes in direction..................-....- 507 
The cyclic movement of recurrent pulses..............-.....0-000-- 509 
Necessity of brief interval of collection.....................--.+-+ 509 
Suggestions of cyclic phenomena in data of other investigators..... 509 
Evidence in, our, récords)....).2--m-reeiee ieee eee eee ee 510 
