FOUNDATION OF A THEORY OF HEREDITY. 



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sexual and asexual (Fig. II) methods alternately, although in the 

 former case the conjugating swarm-cells cannot be distinguished 

 with certainty as male or female. In both kinds of reproduction, 

 each cell in the colony acts as a reproductive cell ; in fact, it 

 behaves exactly like a unicellular organism. 



It is very interesting to find in another genus belonging to the 

 same natural order, that the transition from the homoplastid to the 



