io8 



GEXERAL BIOLOGY 



obtained by the method suggested for obtaining 

 Euglena. More may be gotten from the surface 

 plankton of shallow ponds with a towing net of fine silk bolt- 

 ing cloth. It being impossible to say what forms may be 

 found at any time and place, no detailed outline can.be 



FIG. 65. Volvox (from West, after Klein). The individual cells 

 are united by radiating strands of protoplasm. A, a mature 

 colony ; a, spermaries ; g, ovaries. B, zygote resulting from 

 the fusion of the gametes. C, two sperms D, egg. 



given for the study of them. Suffice it to say that the 

 flagellates available should be compared as to form and activ- 

 ities, the manner of cell aggregation in colonial forms, and 

 differentiation of cells in the colony. And the individual 

 cell should be studied as to its covering, the number, length 



