Brown : Algal periodicity 



22? 



except that the growth was slightly more abundant ; about No- 

 vember 2 1 it settled to the bottom and collected around the edges 

 of the pond. At this time a good part appeared unhealthy. On 



w 



as 



•J 



Q °S 



January 5 it had spread out over the bottom of the pond and w as 



dark- 



green and healthy-looking. It continued to increase in 





