HOW TO KNOW THE 

 FERNS 



CHAPTER I 

 THE FERNS AND THEIR ALLIES 



T N its lowest forms vegetable life is a very 

 J[ simple affair. The minute Algae which 

 clothe damp surfaces with a green film show 

 few indeed of the characteristics with which 

 we are familiar in the higher plants. Certainly 

 they are green, proving that the tiny cells of 

 which they are composed contain the wonderful 

 colouring matter chlorophyll, by means of 

 which they are able to assimilate carbon from 

 the carbonic acid of the air. There is, however, 

 in these lowly plants no sign of a stem, a leaf, 

 or a root. As we ascend in the scale of vege- 

 table life we begin to get an increasing number 

 of distinctive characters. In the case of the 

 Mosses we have plants with distinct stems and 

 leaves. But Mosses have no true roots, neither 

 is there any vascular (woody) tissue in their 

 composition. Mounting yet higher in the scale 

 we come to a very important and interesting 

 group of plants usually referred to as the Vas- 

 cular Cryptogams. In this group are included 

 the Ferns, the Horsetails, and the Club Mosses. 



