THE BEGINNINGS OF LIFE, 



447 



FIG. 85. 



Origin of Diatoms, Desmids, Pediastreae, and Algae from Euglenae and 

 other Vegetal Matrices. (Gros.) 



a. Euglena in early stage of transformation into a Diatom. 



b, c. Two forms of Diatoms which may arise from transformed Euglenae. 

 d, d'. Chlamidomonas giving origin to Diatoms. 



e. One of worm-like Euglenae, which after increasing in size may 

 gradually become converted into aClosterium (f). (Reduced.) 

 g, g', A Euglena undergoes fission, and grows after the manner of 

 Arthrodesmus. 



b. A vegetal vesicle of Moss origin, which divides and develops into 



another form of Arthrodesmus. 



j. One of its separate segments, dividing obliquely into two 

 portions, each of which gradually grows and assumes the 

 characters of a Navicula (k, IS). 



/. A Micrasterias produced by the fission of a Euglena and the ar- 

 rangement of the cohering segments in a single plane. (Reduced.) 



m. C.adophora-like Alga produced from a Eugleua (original X 600). 



