392 



ORGANOGRAPHr. 



Fig. 836. 



a protoplasmic sac, and furnished with cihae, 

 by which they actively move for some time ; 

 they then become immovable, acquire a cel- 

 lulose coat, and germinate. The zoospores of 

 the ti-ichosporangia appear to be closely allied 

 to the spermatozoids. The zoospores are of 

 an olive- brown colour, somewhat pear shaped, 

 and have but two ciliaj of unequal length di- 

 verging from each other. 



2. The Spores, or inactive spores as they 

 may be called in contradistinction to the 

 zoospores, on account of their being motion- 

 less, are situated in sacs called sporangia (^^r. 

 837, sp) or perispores. In rare cases but one 

 spore is contained in each sporangium or peri- 

 spore, as in Halidrr/s, but generally the endo- 

 chrome or contents of the sporangium divides 

 ^mSent*pfEZcaJt m such a manner, as to form two, four, or eight 

 pusvcrminosus,hetiT- spores or sporulcs, cacli of which is capable 

 r7ngiToT7porel?the of germinating. Besides the perispore, the 

 contents are termed sporcs are also enclosed in two other mem- 

 Henfr*ey.** ^^^ brancs, one situated directly within it, called 



the epispore, and a third internal to the latter. 

 These sporangia are either dispersed all over the surface of the 

 frond ; or they are collected in definite groups called sori on its 

 surface ; or on the walls of globose cavities called conceptacles or 

 scaphidia {fig. 837), which communicate with the external sur- 



Fig. 837. 



Fig. 838. 



Fig. 839. 



Fig. H37. Section of a conceptocle of Funis cannliculatus, containing sporangia, 

 «p,; antlieridia ; and paraphyses, par. s. Opening by which the spores escape. 

 After Ilenfrcy Fig. 8;W. Antheridium of Fiini.i .'leridliis, with two ciliated 



Ctozixi or upcnnntoioid.t in its interior. Fig. S39. Filamentous cellular 

 ies. from the inner surface of a conceptacle, bearing anthcridia, a. a. u. p. 

 Paraphyses or abortive iilaments. 



face by a pore. 



These conceptacles are usually grouped 

 (guiuer 111 somcwnat club-shaped or oval receptacles, situated at 

 le summit or side of tlie frond or its divisions (fig. 1 53, t). 

 3. The Antheridia arc little, usually somewhat ovate sacs 



