SEAWEEDS. 297 



because the contents break up into four smaller spores. 

 Sometimes this weed is what botanists term proliferous, that 

 is, it produces new plants upon its frond. Like all those 

 showing iridescence, it is a much more beautiful species in the 

 water than in the herbarium ; though it is not without beauty 

 there, and it is a prize eagerly sought by collectors. 



It is worthy of note that freshwater Algae are, with very 

 few exceptions, green, whilst few of the marine species are 

 truly green; brown and olive, and red, are the prevailing 

 hues. The green marine weeds are nearly all found in shallow 

 water. Of course, they all possess the green colouring matter 

 called chlorophyll, but in the deep-water species, according to 

 Murray and Bennet, "it appears to be essential .... that 

 the green colour of the chlorophyll should be masked by a 

 coloured pigment, red in the case of the Florideae, brown in 

 those of the Phaeosporeae and Fucaceae." It is from these 

 latter classes our examples have been already drawn ; we must 

 now give a turn to the Florideae, which contains many of the 

 most popularly sought species, because they are often so 

 charmingly tinted and so delicate in structure. 



It must not be supposed from the foregoing remarks that the 

 whole of this class are red weeds ; the majority are not only 

 red but brilliant red ; whilst others are purple, brown, yellowish, 

 or dirty-white. They are chiefly small weeds, but they make 

 up for the want of stature in their delicacy of texture and fine- 

 ness of division. 



A very beautiful genus of delicate red and purple weeds, 

 chiefly growing upon the larger and coarser kinds, is called 

 Callithamnion (Greek, Kalli, beautiful, and thamnos, shrub). 

 Some attain the length of half a foot, but most of them 

 are much smaller. They require careful examination with 

 lens or microscope to decide the species, and oftentimes 

 in order to distinguish them from other finely branched red- 

 weeds. For their proper discrimination we advise reference 

 to a book devoted exclusively to Seaweeds, such as Lands- 



