ORGANS OF REPRODUCTION. 



Fig. 831. Fig. 832. 



391 



Fig. 833. 



Fig. 831. Section of the 

 frond of Rhynchococcus 

 coronopifoUus, with te- 

 traspores immersed in 

 its substance. After 



Henfrey Fig. 832. 



Section of a concepta- 

 cle of Hildenbrandtia 

 sanguinea, containing 

 tetraspores. After Hen- 



frey Fig- 833. Sti- 



chidium of Dasya Kut- 

 zingiana, containing 

 tetraspores. After Hen- 



frey Fig- 834. Two 



faveUceot CaUithamnion tetragonum, containing spores 



Fig. 835. Ceramidium of Bonnemaisonia asparagoides, con- 

 taining spores, and terminated by a pore. 



be considered as essential to their functions. " — (Berkley's " In- 

 troduction to Cryptogamic Botany," p. 199 ) 



Zoospores have not at present been found in the Rhodo- 

 spermous division of the Alg£e. 



3. Melanosporece, Fucoidece, or Brown-coloured Algce. — The 

 sexual nature of these Algae is generally considered established, 

 and they are even described by some authors, as Berkley, as 

 monoecious or dioecious. 



In these Alg», as in the Rhodospermous division, the repro- 

 ducti\ie organs seem to be of three kinds: — namely, 1. zoospores ; 

 2. spores ; and 3. antheridia. 



1. The zoospores are found either in large numbers, in peculiar 

 cells called oosporangia, sporangia, or commonly spores, which are 

 placed at the ai*ticulations (^fig. 836), or summits of the divisions 

 of the frond; or singly, in each cell of a jointed thread-like body, 

 which has been called the trichosporangium. These zoospores 

 have essentially the same structure as those previously described 

 in plants of the order Chlorospermece; that is, when discharged 

 from their sacs they have no cellulose coat, but consist merely of 

 c c4 



