188 
BRACHIONUS PALA, TYPE Form. SEXUAL CYCLE. 












eee Winter eggs | Summer eggs See Total 
eo Pe caeed Car- : eggs* ee 
Free* ee Free* | Carried 
ets Oe. poussins Dy (ones a2 06)| === 96 48, 
Novae 765) | 765.|85.| 1700 | 30608) onaasal, me 1885 
Nov. 14..... ‘4,140, 8,280 | 7,245 | — | 63,135 | 71,415 |150,075 | 134, 5350 
Nowe20ee ees | == | 4/,680;| —" "| — | 434680.) 68,880 |114. 240) ) 1acmoam 
Nov, 27.:... == 742 | 2,226 | — | 46,746 | 89,040 |138,754 Bae 
Dace | = |» 4,380. |= = 9.68, 310" | 662400135, 0300 momtenaaim 
Wee. tard: — Aga |) ===) 9/46. 4194 | 17 34400247 On mesomnad 
Dech tes. : | | | | 17,808 | 1,113 | 18,921 | 14,469 
Dee. 25.....| | | i amet al 742 | 371 




* Includes free eggs of other varieties also. 
culmination of a pulse is very large. For example, the sudden ver- 
nal pulse of 716,982 on April 24 is accompanied by 28,584 free 
winter eggs. The pulse declines to 22,224 on April 29, and the free 
winter eggs rise to 95,841, and the empty lorice to 26,114. 
Females carry 1-5 summer eggs, and 1-8, or even more, male 
eggs. There is great variation in the size of ie summer eggs, these 
and the male eggs appearing almost to intergrade. 
Brachionus pala, including Bb. amphiceros, is a common constitu- 
ent of the plankton of shallow warm waters. It has not been 
reported from the larger and cooler lake waters by Apstein (’96), 
Burckhardt (’00 and ’00a), or Jennings (’94, ’96, and ’00). Zacha- 
rias (98) and Marsson (’00) find it in the summer plankton of 
smaller lakes and ponds in Germany. Seligo (’00) records it from 
April to October, with a maximum in August, in Prussian lakes; and 
Lauterborn (’98a) finds it to be perennial and polycyclic in the 
Rhine. Schorler (’00) reports both pala and amphiceros from the 
Elbe, the former being abundant in May and sporadic during the 
summer, while the latter was abundant in April, June, and Septem- 
ber, and rare at other times during the warmer months. Zimmer 
lili 
a tr 8 ER BON OS OED 


