158 INTRODUCTION TO CRYPTOGAMIC BOTANY. 



but they retain their habit in New ZearanJ, and, probably, in 

 many other southern dimes. Their fruit is either lateral or 

 terminal, often in pairs, accompanied by curved antheridia 

 (Fig. 25), which have already been described, p. 89. The 

 species are mostly determined by the situation and character 

 of the fruit, which appears under many modifications. In 

 Vaucheria clavata, the spores, instead of being quiescent, are 

 clothed with minute cilia, like those on the mucous membrane, 

 and are, in consequence, endowed with active motion. Whe- 

 ther, in this case, there are also spermatozoids, is still a ques- 

 tion. In many genera, however, the fruit consists of far 

 smaller zoosj)ores, with delicate flagelliform appendages. The 

 marine genus Bryopsis is remarkable for the regular arrange- 

 ment of the divisions of the component cell. The species are 

 mostly parasites on other Algse, and produce innumerable 

 minute zoospores, by which they are propagated. Cysts also 

 are occasionally produced, but it does not appear that they 

 ever have true spores like those of Vaucheria. 



132. The compound species abound on sandy coasts, more 

 rarely on rocks,* or in deep water, affecting generally warm 

 climates, but the genus Codhim ascends to high latitudes, 

 and appears under four different forms on our own coasts, 

 in three instances inhabiting deep water, or rocks never 

 uncovered except at spring tides, and in the fourth, occupying 

 turfy banks, exposed to the spray. The zoospores are large 

 and strongly granulated with a pellucid apex, and two delicate 

 appendages. 



133. Of those green Alg^ which are masked by calcareous 

 matter, there are two series distinguished by their monosipho- 

 nous or polysiphonous stems. Of the latter, I have already 

 spoken under Confervacece, under the impression that they 

 are really more allied to the articulate than the inarticulate 

 Algas. It is clear, however, that all is not yet known about 



* In the Eed Sea, some of the species root into madrepores, others 

 grow on rocks, and sometimes, where these hang over, tlie fronds are 

 directed downwards. Their tips, as observed first by M. Botta, are 

 often yellow, while the base is green, a fact which may be verified in 

 any herbarium. 



