— 107 — 



Text-figure I. A. Oedogonium mulfisporum, Wood, with oogonia an<l 

 dwarf-males; B. Oedogonium Pringsheimii, Cram., forma, filaments showing 



the différent shapes of oogonia ; C. Spirogyra quadrata (Hass.), Petit. The 

 upper filament shows cells with two and one spiral , in the lower part of the 

 figure a lilament with two spirals is shown conjugating with one having 



one spiral. 



