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MANUAL OF POISONOUS PLANTS 



Fig. 19. Algae found in water supplies, a. Protococcus. b, c. Cosmarium, one of the 

 desmids. d. Pediastrum. e. Oscillatoria. f. Nostoc paludosum. g. Closterium, chr 

 chromatophore. h. Pandorina; 1, gelatinous envelope; 2, cilia, i, j. (Anabaena flos-aquae). 

 k. Botrydium granulatum; 2, rhizoids. I and m. Diatoms, n. Zygnema; 1, chromatophore; 

 2, zygospores. o. Spirogyra; 1, 2, 3, 4, different stages in the formation of the zygospores. 

 p. Draparnaldia', 2, thallus. q. Stone-worts (Chara) ; 1, antheridium; 3, archegonium; 5, 

 nodal cells, r. Portion of antheridium with sperm cells. 



