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A TEXTBOOK OF THEORETICAL BOTANY 



Fig. 561.— Azolla filiculoides. A to E, Stages in the development of the 

 archegonium. F, Two-celled embryo. G, Young embryo. {After 

 Smith.) 



COTYLEDONS 



ROOT 



Fig. 562.— Azolla filiculoides. A, Longitudinal section through 

 a mature embryo. B, Embryonic plant still attached to the 

 megaspore. {After Eanies.) 



