510 PICKETT: CHANGED POLARITY IN SPIROGYRA ELONGATA 
sketch is shown in TEXT FIG. 1. This too was evidently a holdfast, 
although it is not now known to what the filament was attached. 
Fic. 1. Spirogyra communis, X 425, as observed and drawn by Professor F 
M. Andrews, Nov. 1, 1904 
Entirely different from the cases given above are those shown 
in FIG. 7 and 8 (PLATE 36). When it is taken into consideration 
that these two filaments were normal, rapidly growing vegetative 
filaments, and that no indication of fruiting activity could be found 
in the whole collection under consideration, the change of polarity 
here shown seems very unusual. There is no suggestion, either in 
form or in the proximity of other filaments, of these branches being 
holdfasts. So far as the writer can find, such forms have not been 
found in nature or under conditions of controlled experiment. 
The drawings were made with an Abbe camera lucida and 
Leitz obj. 6 and oc. 4. 
INDIANA UNIVERSITY, 
BLOOMINGTON, IND. 
