BKITISH CHAKOPHYTA. 



INTRODUCTION. 



The Charophyta are a small group of Cryptogams, 

 and occupy a peculiarly isolated position, having no 

 clear affinity with any other plants. The species all 

 the world over probably do not number much more 

 than two hundred. They are exclusively aquatic in 

 habit, living in normal conditions entirely under water, 

 and from this fact, added to their fragile and perish- 

 able character and their apparent lack of economic 

 value, they have attracted little attention from any 

 but botanists, indeed it may be safely conjectured that 

 the majority of generally well-informed people are not 

 even aware of their existence. 



To the botanist, on the other hand, their curious 

 and unique structure, and the uncertainty as to their 

 position in the Vegetable Kingdom, have invested them 

 with a peculiar interest, and as a consequence they 

 have given rise to an extensive literature, quite out of 

 proportion to their apparent importance. For a while 

 teaching botanists were wont to select some species of 

 Charophyte as one of their plant-types. The simplicity 

 of the vegetative parts, the exceptionally large size of 

 their cells, owing to which structure and development 

 could be easily seen, added to the facility by which, for 

 the same reason, the process of cyclosis could be 

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