217 



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 a small group of plants known 

 by the name of Ephedra, and belonging to the order Gneta- 

 cecEj and also to another limited set called Casuarina ; but 

 this resemblance is confined to their general aspect, and is 

 in great measure owing to the peculiar jointing of the stems 

 and branches. With Perns 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 (Marchantiac&z) ; and they 

 have also some analogy with the aquatic group, Characece. 



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 membranous 



