1. Growth efficiency ofDaphinia magna. I. The effect of food concentration

   • Kees Kersting

   OriginalPaper Pages: 3 - 20

2. The macrobenthos of the river IJssel

   • G. Van Urk

   OriginalPaper Pages: 21 - 29

3. Abundancy estimations of aDaphnia magna population in a small artificial pond

   • Robert Lingeman

   OriginalPaper Pages: 30 - 38

4. Water quality research in the area of the river Kromme Rijn

   • B. Beltman
   • W. Bleuten

   OriginalPaper Pages: 39 - 51

5. Environmental changes in the Oisterwijk moorland pool area, evident from the composition of the desmid flora

   • P. F. M. Coesel

   OriginalPaper Pages: 52 - 53

6. Changes in the moorland pools near Oisterwijk between 1840 and 1975

   • H. van Dam
   • H. Kooyman-Van Blokland

   OriginalPaper Pages: 54 - 55

7. Publications

   • H. van Gemerden
   • S. Parma
   • Jaap Dorgelo

   BookReview Pages: 56 - 60

8. Congresses

   Announcement Pages: 61 - 62