238 Brown : Algal periodicity 



March 



This was rather 



healthy and growing for a time. It became rather abundant on 

 the east side of the pond during the latter part of April and the 

 first of May. Then it began to become unhealthy looking, the 

 cells of the filaments coming apart. From this time on it gradu- 

 ally disappeared, none being found June 25. Ulothrix zonata 

 appeared in the lower part of stream no. 1 the middle of July. It 

 seemed to be healthy and growing, was a bright-green, with fila- 

 ments a foot or two long, attached at one end, the other floating. 

 It disappeared in a few weeks. A small amount of Coleochaete 



Typh 



J 



A small amount of Sticlwcocats was found growing on the dry 

 clay soil clinging to the roots of a large tree that had blown down 

 along stream no. 2. The soil was sheltered so that it was usually 

 rather dry. This was first noticed early in the winter. It 

 remained in a growing stage during the entire winter, reaching its 



ince in March. During the latter part of May 



J 



Doubtless the soil became 



too dry and the temperature too warm. • 



A limited amount of Herpostciron was epiphytic on Oe. eras- 

 siasatlum in pond no. 1 during March and April. 



Representatives of three genera belonging to the family Chae- 

 tophoraceae were found — Chaetophora, Myxoncma, and Drapar- 

 naldia. Chaetophora was the most abundant, appearing in con- 

 siderable quantities in pond no. i and stream no. I (see charts). 



Chaetophora pisiformis was rather abundant in pond no. I, 

 September 20, 1906, appearing as small glistening greenish 

 globules attached to submerged objects. It continued to be 

 rather abundant until the last of November, when it disappeared ; 

 appearing again about the middle of March, it spread over the 

 pond and became very abundant in distribution especially, coating 

 nearly everything submerged in the pond. It continued abundant 

 to the first of August, being the dominant alga of the pond 

 the greater part of the time. The same species appeared in the 

 upper part of stream no. 1, November 15. It was abundant for 

 about a month, attached to sticks, grass, and stones on the bottom 

 of the " branch." The masses here seemed to be much larger than 



