THE BEGINNINGS OF LIFE. 



417 



FIG. 82. 

 Modes of Origin of Desmids and Diatoms. 



a. Green algoid corpuscles contained within a hyaline envelope which 

 buds from a Cladophora filament. ( X 600.) 



b, c. Outgrowth of Desmids from the surface of Nitella filament the 

 base being surrounded by a dark brown zone, which persists (d) 

 after the Desmid has disappeared. ( x 600.) 



e, e'. Other filamentous Desmids, springing from a green thalamus which 

 is surrounded by the brown zone. Pediculated Diatoms were 

 also seen budding from the same Cladophora filament, 

 (x 600.) 



/. An algoid vesicle (x 600) budded off from Vaucheria, whose 

 elongated corpuscles frequently increased in size and became 

 liberated from their envelope (g), after which some of them 

 grew into Desmids (b, h',j, ). Other vesicles (g'} gradually 

 become converted into different kinds of Diatoms (/, /', m, 

 ro')- (X 1750.) 



n, '. Origin of Desmids from chlorophyll corpuscles of Vaucheria. 

 (x 600.) 



VOL. II. 



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