"... ', one of the largest of the , was produced in enormous quantity by natural means. The blue-green alga, , contributed directly to its support and proved to be the most desirable food of a heavy, natural culture of Daphnia pulex. The author's first observation of this association in the pond occurred on June 21, 1918. At this time a "bloom" of the Aphanizomenon was approaching it maximum. It was so abundant that the water appeared blue-green and oily. A few hand strokes of the net would bring up a of it in concentrated form."