i?o ABOUT HORSETAILS, [CHAP. 



But from one of the cells a number of little processes 

 are given off, and from the centre of these a bud, like 



the growing point 

 of an adult stem, 

 arises, and gradu- 

 ally produces a 

 new plant, with 

 stemand branches, 



roots and reproductive organs complete. In fig. 128 

 S is the detached sporangia, which has given rise to 

 the pro-embryo P.Em, with its root R, and bud B. 



It should be noted that in Cham there are no 

 vessels. The whole plant is built up of cells, each 

 being originally of the simple form of cells, but some 

 of them becoming ultimately modified. Thus the 

 antherozoids are at first simple cells, becoming modi- 

 fied for a special purpose, 



From the simple character of the organisation in 

 these plants, the order occupies a low position in the 

 classification of flowerless plants. Their place is be- 

 tween the Crystalworts (Ricciacccz] and the Algae. 



It remains for us to notice the British representa- 

 tives of an order called Marsileacece, or Pepperworts. 

 There are but three British species, one of these 

 Isoetes Moorei having been discovered by Dr. Moore, 

 as recently as 1879, in Upper Lake, Bray, co. Wick- 

 low. 



The English species are but two, each belonging to 

 a different genus. They are both aquatic plants. 



Isoetes lacnstris, the Quillwort, or Merlin's Grass, 

 grows on the bottoms of lakes, being completely sub- 

 merged, when it has the appearance of grass. The 

 stem or root-stock is globular in form, and gives 



