1. Some limnological observations in the lakes of the “Oostelijke Vechtplassengebied”

   • R. D. Gulati

   Papers and Summaries of Scientific Meetings Organised by the Netherlands Hydrobiological Society Pages: 3 - 9

2. Studies on the food, grazing and metabolism of a filterfeeders community of zooplankton in the lakes Vechten and Tjeukemeer

   • R. D. Gulati

   Papers and Summaries of Scientific Meetings Organised by the Netherlands Hydrobiological Society Pages: 10 - 12

3. Concentration changes of some elements during a year cycle in Lake Vechten

   • H. Verdouw

   Papers and Summaries of Scientific Meetings Organised by the Netherlands Hydrobiological Society Pages: 13 - 13

4. Pleomorphism inScenedesmus quadricauda (Turp) Bréb. (Chlorophyceae)

   • C. L. M. Steenbergen

   Papers and Summaries of Scientific Meetings Organised by the Netherlands Hydrobiological Society Pages: 14 - 14

5. Nutrient content of the aquatic macrophytesElodea canadensis andCeratophyllum in the course of the year

   • P. H. Best

   Papers and Summaries of Scientific Meetings Organised by the Netherlands Hydrobiological Society Pages: 15 - 16

6. The possibilities of a new kind of micro-ecosystem in aquatic ecosystem research

   • J. Ringelberg

   Papers and Summaries of Scientific Meetings Organised by the Netherlands Hydrobiological Society Pages: 17 - 18

7. A limnological study of some man-made lakes in the province of South Holland

   • G. Bolier
   • A. N. Van Breemen

   Papers and Summaries of Scientific Meetings Organised by the Netherlands Hydrobiological Society Pages: 19 - 29

8. Further observations on drift in two brooks in Auvergne (France)

   • Jaap Dorgelo

   Papers and Summaries of Scientific Meetings Organised by the Netherlands Hydrobiological Society Pages: 30 - 30

9. Introduction to the research carried out in a ditch of the “Oostelijke Binnenpolder” at Tienhoven during a camp of the Netherlands Hydrobiological Society

   • B. Beltman

   Papers and Summaries of Scientific Meetings Organised by the Netherlands Hydrobiological Society Pages: 31 - 34

10. Some physical and chemical characteristics of the ditch at Tienhoven

    • B. Beltman

    Papers and Summaries of Scientific Meetings Organised by the Netherlands Hydrobiological Society Pages: 35 - 36

11. Survey of the macrovegetation in a ditch near Tienhoven (Utrecht, the Netherlands)

    • L. DE Lange

    Papers and Summaries of Scientific Meetings Organised by the Netherlands Hydrobiological Society Pages: 37 - 39

12. Periphyton diatoms in a ditch near Tienhoven

    • E. J. P. J. Mols

    Papers and Summaries of Scientific Meetings Organised by the Netherlands Hydrobiological Society Pages: 40 - 47

13. Distribution of multicellular benthic algae in an eutrophic ditch

    • H. Hillebrand
    • S. P. Klapwijk

    Papers and Summaries of Scientific Meetings Organised by the Netherlands Hydrobiological Society Pages: 48 - 58

14. The cladocera of a ditch at Tienhoven

    • E. Notenboom-Ram
    • H. Van Der Hammen
    • P. Van Der Vet-Kappetein

    Papers and Summaries of Scientific Meetings Organised by the Netherlands Hydrobiological Society Pages: 59 - 65

15. Observations on the macrofauna of a Dutch ditch

    • L. W. G. Higler

    Papers and Summaries of Scientific Meetings Organised by the Netherlands Hydrobiological Society Pages: 66 - 73

16. Report of the fish research in a ditch at Tienhoven on 25th August, 1975

    • N. C. Van Doorn

    Papers and Summaries of Scientific Meetings Organised by the Netherlands Hydrobiological Society Pages: 74 - 77

17. In memoriam Mej. Drs. A. M. J. Bouwhuis

    • Hannie Geelen

    Announcement Pages: 78 - 78

18. Biosystematics and ecology ofRhizoclonium riparium (Roth) Harv. (Chlorophyceae: Cladophorales) in the estuarine area of the rivers Rhine, Meuse and Scheldt

    • C. den Hartog
    • H. E. Coomans

    Publications Pages: 78 - 80

19. De Nederlandse invertebraten data bank

    • C. F. Den Stoppelaar

    Varia Pages: 80 - 81