63 



CHAPTER IV. 



RED-SPORED AND GREEN-SPORED ALGM. 



With this chapter we begin the account of 

 another sub- class of algse, the Rhodosperms, or 

 red-seeded. The plants belonging to this class 

 are among the most beautiful of the algse, that 

 is, when they are placed in favourable situations ; 

 for they also change their colours, and as their 

 most beautiful colour is their natural tint, any 

 change is for the worse. Some of them even 

 become brown when there is too much light for 

 them. 



About low water-mark may be found growing 

 largish masses of a dense, thread-like, reddish 

 foliage, sometimes adhering to the rock, or some- 

 times even fixed to the stems of the Laminaria. 

 When removed from the water the plant does not 

 collapse, like many of its relatives, but each 

 thread and branch preserves its own individuality. 

 This is one of the large genus Polysiphonia, and 

 the specific name is ^^urceolata." See plate k, 

 fig. 2. 



