THALLOPHYTA— ALG^ 



45 



Certain conceptacles in some of the PucaceEe do not give rise 

 to sexual organs. These are generally known as cryptostomata. 



Fig. 794. 



Fig. 796. 



Fig. 795 



Pig. 797. 



Fig. 794. Vertical section of a female conceptacle of Fncus vesicttloms con- 

 taining oogonia and paraphyses. After Thuret. Fig, 795. Antheridia, 



a, a, on tlie branched hairs of the male conceptacle. After Thuret. 



Fig. 796. Oogonium with the oospheres fully separated, and disengaging 



themselves from their coverings. After Thuret, Fig. 797. An oosphere 



without a cellulose coat being fertilised by antherozoids so as to form an 

 oospore. 



These cavities contain only paraphyses, vrhich are of greater 

 length than those in the fertile conceptacles. 



The Laminaeiace«: afford examples of the largest Algse of the 



