Index. 



451 



Spring, algae in, 356. 



Crustacea in, 307. 



temperatures, 291, 323. 



vertical distribution in, 380 . 

 Sprungschicht, see thermocline . 

 Stations, position of, 276. 

 Summer, Crustacea in, 309. 



temperatures, 293. 



vertical distribution in, 382, 393. 

 Surface, vertical distribution near, 407. 



swarms at, 371. 

 Swarms, 366, 371. 

 Syncheeta, 307. 

 Tables, statistical, 437-448. 

 Temperature, 286. 



in April, 323. 



in autumn, 299 . 



at bottom, 290, 292, 299. 



diagrams, 288. 



effect on algae, 307 ; on appearance of Crus- 

 tacea, 323; on Crustacea, 358; on Cy- 

 clops, 306, 308; onDiaptomus, 324; on 

 Nauplii, 307, 360; on reproduction, 

 306, 358 ; on the sinking of algae, 417 ; 

 on vertical distribution, 421, 



effect of wind on, 292. 



errors in, 287. 



maximum, 294. 



methods of study, 286. 



of mud, 290. 



number of observations, 288. 



relation of, to effect of light, 423. 



in September, 324. 



in spring, 291. 



in summer, 293. 



at thermocline, 295. 



in winter, 289. 



winter rise of, 290. 

 Thermocline, 295. 



effect of wind on, 299. 



effect on vertical distribution, 383, 422. 



movement of, 298. 



variation of temperature at, 298. 



vertical distribution at, 415. 

 Thermophone, 286. 

 Triarthra, 307. 



Variations in number, 281, 306, 315, 335, 343, 

 351, 368 ff., 405. 



in vertical distribution, 392, 432. 



See Tables of Appendix. 



Vertical distribution, 375. 

 affected by age, 398, 431 ; by chemical con- 

 dition of water, 423; by clouds, 410, 

 426 ; by food, 419 ; by gravitation, 429 ; 

 by light, 409, 425 ; by temperature, 421 ; 

 by wind, 427. 

 in autumn, 386. 



of Chydorus, 382, 389, 404, 407, 446. 

 of Cyclops, 379, 381, 393, 395, 407, 413, 416, 



418, 422, 441. 

 of Daphnia hyalina, 383, 387, 393, 397, 407, 



413, 416, 422, 426, 443. 

 of Daphnia pulicaria, 379, 381, 385, 388, 399, 



413, 415, 421, 427, 445. 

 of Daphnia retrocurva, 402, 407,413,416,446. 

 of Diaphanosoma, 403, 407, 409, 413. 416. 



425, 447. 

 of Diaptomus, 383, 393, 394, 407-410, 411, 



416, 418, 422, 439. 

 of Epischura, 412. 

 of Ergasilus, 333, 413, 416. 

 independent of numbers, 384, 392, 394. 

 of Leptodora, 404, 407, 411. 

 methods of study, 376, 408, 417. 

 of Nauplii, 405, 416, 432. 

 at night, 410. 



Percentile, 384, 390 and Appendix. 

 specific peculiarities, 432. 

 in spring, 380. 

 near surface, 407. 

 in summer, 382. 

 tables, statistical, 437-448. 

 at thermocline, 415. 

 in upper meter, 407. 

 variations in, 392, 410. 432. 

 in winter, 378, 426. 

 Wesenberg-Lund, 307. 

 Whipple, 282, 295. 



Wind, effect of, on temperatures, 291,295,299. 

 on thermocline, 297, 298. 

 on vertical distribution, 410, 415, 427. 

 Winter, crustacea in, 305. 

 reproduction in, 291, 306. 309, 321, 329, 335. 



359, 361, 364. 

 temperatures, 289. 

 variation of numbers in, 368. 

 vertical distribution, 378. 

 Young crustacea, number of, in upper 



meter, 409. 

 Zacharias, 331, 347, 356. 



