H^MATOCOCCUS 



LESS. 



the fact in another and fairer way, that they travel a distance 

 equal to two and a half times their own diameter in one 

 second. In swimming the pointed end is always directed 



FIG. 3. A. Hamatococcus pluvialis, motile phase. Living specimen, 

 showing protoplasm with chromatophore (chr) and pyrenoids (pyr), 

 cell-wall (c. ?v) connected to cell-body by protoplasmic filaments, and 

 flagella (fl. ). The scale to the left applies to Figs. A D. 



B. Resting stage of the same, showing nucleus (nu) with " nucleolus " 

 (nu'}, and thick cell-wall (c. w) in contact with protoplasm. 



c. The same, showing division of the cell-body in the resting stage 

 into four daughter-cells. 



D. The same, showing the development of fiagella and detached cell- 

 wall by the daughter-cells before their liberation from the enclosing 

 mother-cell-wall. 



E. Hczmatococcus lacustris, showing nucleus (M(), single large 

 pyrenoid (py)'), and contractile vncuole (c. vac). 



F. Diagram illustrating the movement of a flagellum : ab, its base ; 

 c, c', c", different positions assumed by its apex. (E, after Biitschli. ) 



