ARKIV FÖR BOTANIK. 



BAND 17. N:o 13. 



riie pliytoplaiiktoii of some artificial pools near 



Stockholm. 



By 



GILBERT MORGAN SMITH. 

 The University of Wisconsin. Madison, Wis , U. S. A. 



With 1 Figure in the text. 



iommunicated September 14th 1921 by G. Lagerheim and C. Lindman. 



In June of 1920 while on an expedition with Dr. 0. 

 Jorge, a plankton catch was made from a small artificial 

 rnamental pool in front of the castle at Rydboholm, north- 

 ast of Stockholm. Examination of this material showed 



many striking organisms that collections were also made 

 rom the artificial Monocotyledonous and Dicotyledonous pools 

 f the Stockholm Botanical Garden (Hortus Bergianus) in 

 he hope that these too might have an interesting plankton 

 lora. While no plankton algae of great interest were found 



1 these latter pools, the results are incorporated in the 

 able of organisms observed as a contribution towards our 

 nowledge of the plankton flora of artificial pools. 



The frequency of the different algae at the various sta- 

 ions is shown by the following abbreviations in the table: 

 rr) very rare, (r) rare, (ss) very scarce, (s) scarce, (c) com- 

 lon, (cc) very common. 



ylr/i-iv fir holunik. Hand 17. N:o 1.1. 1 



