DISTRIBUTION OF FOLLICULINA IN 1914. 375 



feeding of the menhaden upon plankton in which the free swim- 

 ming Folliculina may be included as possible food for the men- 

 haden. 



At this date the Elodea had grown up to a height of twenty 

 inches and formed some flower stalks and buds at the surface, 

 so that there had been a long period in which suitable attachment 

 base for Folliculina was present but the Folliculina had been 

 absent. 



July 21 the water after long drought was turbid from the 

 presence of plankton and the Folliculina had increased but little, 

 appearing as black spots on one out of several hundred sprays of 

 Elodea and one out of many thousands of Potamogeton sprays. 

 Only a few of the leaves on each inhabited spray had dense 

 aggregates, so that the question arises: why do the Folliculina 



FIG. 2. Tip of leaf of Elodea covered with a colony of Folliculina. X IS diam. 

 Photograph of preserved specimen. 



crowd together in these rare, isolated aggregates? When sprays 



L 



of these dates were put into aquaria they gave rise to free swim- 

 ming forms, thus showing that these early settlers need not 

 remain fixed but might contribute to additional distributions. 



On July 27 Folliculina had become much more abundant upon 

 sprays of Elodea and Potamogeton; some of the free-floating frag- 

 ments on the surface appeared black with the accumulated 



