206 
degree than of any other species of Spirogyra that was tested. Since 
the phenomenon was observed once in a physiological condition that had 
been made favorable for conjugation and again where conjugation was 
actually taking place, it was at first thought that the branches were exag- 
gerated attempts at conjugation, and, in some instances, this may have 
been the case. But the filaments were usually close enough together that 
such long tubes would not have been necessary, and no actual union of 
gametes as a result of any such activity was at any time observed. 
Moreover, the filaments shown in Fig. 4 illustrate a condition noted in two 
or three cases, where filaments having mature zygotes in some of their cells 
were attached by these branches to others also containing zygotes. The 
filament shown in this figure as holding to another by means of the foot- 
like branch was a long one and had at another place mature zygotes that 
had been formed as a result of Conjugation with some other filament. If 
these branches were modified conjugating tubes, a relation of this sort 
would be out of harmony with the tendency toward bisexuality that is 
usually exhibited by the plant. 
Indiana University, 
Bloomington, Indiana. 
LITERATURE CITED: 
(1) Wolle, Rev. Francis. Fresh water alge of the United States. 1887. 
(2) Collins, Frank S. Green alge of North America. 
Tufts College Studies, Vol. II, No. 3. 1909 
(3) Wood, Horatio C. Jr. A contribution to the history of the fresh water algw of North 
America. 
Smithsonian Contributions, No. 241, Vol. 19. 1872. 
(4) Pickett, F. L. A case of changed polarity in Spirogyra elongata. 
Bul. Tor. Bot. Club, Vol. 39. 1912. 
(5) Weatherwax, Paul. Aphanomyces phycophilus De Bary. 
Proc. Ind. Acad. of Se. 1913. 
