ORGANS OF REPRODUCTION. 



373 



terior of each sporocarp is divided usually into four cells {fig- 

 793), and when ripe it opens by four valves. In the interior 



Fig. 790. 



Fig. 791. 



Fig. 792. 



Fig. 790. Fructification of a species of 3rarsilea. 

 s. Two-valved sporocarp. p. Peduncle. /. 



Fructification Fig. 791. Antheridium of 



the above Fig. 792. Ovule or sporangium 



of the above. After Maout. 



of each cell there is a mucilaginous process or placenta at- 

 tached to the walls, upon which are placed numerous anthe- 

 ridia and sporangia or ovules, as in Marsilea. The structure 

 of these antheridia and sporangia resembles in all essential par- 

 ticulars those of Marsilea. In fact, the only diflference between 

 the fructification of Marsilea and Pilularia, is the more compli- 

 cated nature of the sporocarps in Marsilea. 



The fructification of Salvinia (Jig. 794) and Azolla, appears 

 to resemble that of Marsilea and Pilularia, except that the anther- 

 idia, a, and sporangia or ovules, b, are here contained in 

 separate sacs, and are attached to a sort of central cellular 

 placenta {fig. 794). In germination also, the pro-thallus of 



Fig. 793. 



IKffl 



Fig. 793. Transverse section of the sporocarp or spore-fruit of Pilularia glohuli- 



fera. After Henfrey Fig. 794. Vertical section of the sporocarp of <SaZi;inia, 



showing sporangia in one cavity, 6, and antheridia in the other, a. 

 BB 3 



