24 



HiEMATOCOCCUS 



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. Hamatococctts pluvialis, motile phase. Living specimen, 

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

 cell-wall \c. w) connected to cell-body by protoplasmic filaments, and 

 flagella {Ji. ). The scale to the left applies to Figs. A — i). 



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

 (««'), 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 flagella and detached cell- 

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

 mother-cell-wall. 



E. Hcematococctis lacustris, showing nucleus (««), single large 

 pyrenoid {f'y>'), and contractile vacuole (c. vac). 



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

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



