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THE BRITISH HORSETAILS. 



This race of plants bears an aspect altogether different 

 from that of the groups in whose company they are placed 

 in books ; and indeed they have no very obvious affinity 

 to any existing order of plants. In their mode of growth 

 they have a certain resemblance to two small groups of 

 plants, the Ephedras and Camarinas, but this resem- 

 blance is confined to their general aspect, and is in great 

 measure owing to the peculiar jointing of the stems and 

 branches. With Ferns and Club-mosses they have little 

 in common, though so frequently associated with them in 

 books. Their most direct relationship is probably with a 

 small group called Liverworts {Marchantiacew), and the 

 aquatic group Characeca. 



The Horsetails are distinguished from other plants by 

 the following characteristics. They are leafless, branching 

 plants, with fistular jointed stems, separable at the joints, 

 where they are solid, and at these points surrounded by 



R 2 ^ 



