SEX UA L REPR OD U CTION. 



287 



Simple ovaries occur only in the algseand fungi, where they 

 are known as oogonia or carpogonia. They are either pro- 

 duced by the modification of one of the cells of a filament 

 (fig. 325), or they are the terminal cell of a special branch 

 (fig. 308). Usually the ovary is decidedly larger than the or- 

 dinary vegetative cells. The fertilized egg often becomes a 

 resting spore (fig. 325). 



in the higher algae, especially the marine algae, the ovaries 

 are often aggregated in special pits, the conceptacles, as in 



m 



Fig. 326.- A section through a female conceptacle of bladder wrack (Fucks vesiculo- 

 sits); showing form <il pit. the numerous hairs with which it is lined, and ovaries in 

 various stages . . t development. In the tissue about the pit note the cortex oi densely 

 plated cells and the loose network of filaments in the interior. Magnified 50 diam. — 

 After Thuret. 



Fucus (figs. 42, 326). Here the ovary is formed by the en- 

 largement of the terminal cell of a two-celled outgrowth from 

 the surface (\'\y;. 327). The eight eggs are set free and are 

 fertilized in the water 1>\ the motile sperms (fig. 324). They 

 grow at once into new plants. 



The simple ovary is surrounded in Chara (fig. 313) by a 

 jacket of spirally coiled cells, which grow up from beneath it 

 and make it look as though it were compound (•' 390). 



