THE BEGINNINGS OF LIFE. 



447 



I 



Fig. 85. 



Origin of Diatoms, Desmids, Pediastreae, and Alga? from Euglenee and 

 other Vegetal Matrices. (Gros.) 



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



h, c. Two forms of Diatoms which may arise from transformed Euglenje. 

 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. 



_;. One of its separate segments, divi(iing obliquely into two 

 portions, each of which gradually grows and assumes the 

 characters of a Navicula {k, V). 

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

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



m. Cladophora-like Alc;a produced from a Euglena (original X 600). 



