1 80 CLASSIFICA TION PABT n. 



plants. As already stated, they are without exception 

 aquatic plants. They comprise three distinct orders, 

 the Chlorospermeae, having green spores ; the Khodo- 

 spermese, having red spores ; and the Melanospermese, 

 having olive-coloured spores. These groups embrace 

 all the varied plants known as sea-weeds, as well as the 

 cellular plants which are developed in fresh water. 



The Chlorospermese are separable into three groups, 

 namely, those which are simply cellular, including the 

 Palmellese, the green Desmidiacese, and the yellow- 

 brown silicious-coated Diatomacese; those which are 

 filamentous, called generally confervas, and including 

 the true Confervacese, in which the threads have no 

 compound axis, the Batrachospermese, in which the 

 threads are partially incorporated with an axis, the 

 Nostochinese, in which the slender moniliform threads 

 are invested with a mucous or gelatinous mass, the 

 Oscillatorise, and some others; and those which are 

 foliaceous, comprising the Ulvacese. All these are monoe- 

 cious plants, whose reproductive bodies are zoospores 

 provided with ciliary appendages, or motionless cysts 

 filled with endochrome, true spermatozoids being rarely 

 present. 



The Ehodospermese divide primarily into two groups 

 defined by the nature and position of their spores : one 

 having the spores indefinite, produced within mother 

 cells ; the other having the spores single in the upper 

 joints of the threads of the nucleus. . The first group 

 includes the Ceramiacese, which are filiform articulate 

 plants, with the nucleus naked, and the Ehodymeniacese, 

 which are compound inarticulate plants, with the spores 

 generated within the cells of moniliform. threads. The 

 second group includes, amongst others, the Rhodome- 

 liacese and the Laurenciacese, the former articulate, the 

 latter inarticulate, and both bearing terminal spores, 

 and having the nucleus conceptacular. To this group 

 also belong the calcareous Corallinacese and the cartila- 



