MICROSCOPE IN THE COU^"TKY. 5o 



twisted hair-like threads (c), which are called the 

 " peristome." These processes are held together by 

 minute teeth (d). The spores (e) are found in the 

 interior ot the urn. All these parts are subject to 

 great varieties in different kinds of mosses. 



From the mosses we may pass on to the feins. 

 Like the mosses, they have no regular flowers, and 

 the parts which correspond to the urns of the 

 mosses are the small brown scaly-looking bodies 

 seated on the back of the fronds, or leaves. In the 

 male fern the little brown bodies which contain 

 the spores are round, as seen in figure 113, and in 

 the common brakes they are placed on the edge of 

 the fronds, as at figure 114. These organs, which 

 are called " sori," may be easily seen as opaque 

 objects, under the lower powers of the Microscope. 

 In the common hart's-tongue, or scolopendrium, 

 the sori are arranged in elongated bands. In this 

 case the sori are covered with a membrane called 

 an "indusium." On opening this, the sori are 

 found lying close together. Each one of these sori 

 is found to be made up of a number of cases called 

 capsules, or " thecse," attached to a stalk by which 

 they are fixed to the frond. This organ is seen at 

 figure 115. These thecse are beautiful objects 

 under the Microscope. Springing from the top of 

 the stalk is a series of cells which surround the 

 case, forming what is called the "annulus." TLis 

 ring possesses an elastic power ; so that when it 

 breaks, the capsule is torn open, and the spores 

 in the inside escape. The spores are covered over 

 with little spines, as at a, in the same figure. The 

 spores of ferns are often called seeds, but they are 

 more like buds than seeds. If one of these spores 

 is watched during its growth, it will be found that 

 it grows into a little green membranous expansion, 

 on the surface of which the two sets of orgaiis 



