The Lower Plants 65 



pigment, and in both color and structure show a 

 certain resemblance to some of the green algae 

 with which they may be, perhaps, remotely related. 



Whatever may have been their origin, the red 

 algae, as they now exist, are very highly specialized 

 plants with no evident relation to any higher plant 

 types, and their peculiarities, including the character- 

 istic red pigment, which gives them their name, are 

 presumably adaptations to their marine environment. 



Reproduction in Algae. The algae exhibit great 

 diversity in their reproduction, which may be sexual 

 or asexual. Several forms of budding or simple 

 fission of the plant body are common and in a 

 few forms it is the only reproduction known. 



Thus in all unicellular species, and in many of 

 the lower multicellular forms, the individual plant 

 breaks up into two or more portions, each 

 of which becomes at once a new individual. 

 Very often special reproductive cells are formed, 

 which are able to develop without fertilization 

 into new plants. The commonest of these non- 

 sexual reproductive cells are the zoospores. In the 

 formation of these zoospores the protoplasm escapes 

 from a cell, either in a single mass or after a pre- 

 liminary division into two or more parts, and these 

 on escaping into the water are seen to be provided 

 with cilia by which they swim rapidly about before 

 they settle down and grow into new plants. In their 

 motile condition the zoospores so closely resemble 

 the low organisms known as Flagellata, and those 



