FERNS. 



687 



of which we must be very brief in our description, not that the subject is 

 not worthy of a much larger space than we can devote to it, but our pages 

 are not elastic. 



There are numbers of plants without pistils or stamens properly so 

 called. They are hidden from human observation buried out of sight ; and 

 in the fern, moss, and other primitive plants they are thus hidden. There 



are several families of the crypto- 

 gamia, but two main sections include 

 them all viz., the cormogens and 

 thallogens. These are sometimes 

 known as cormophytes and thallo- 

 phytes, but the former will be our 

 terms, and they include the ferns, 

 algae, lichens, and mosses, with many 

 other families, which we do not 

 propose to examine in this summary 

 sketch. The microscope will here 

 be a great aid if not always abso- 

 lutely necessary for any close in- 

 vestigation. 



We are all familiar with the 

 appearance of ferns, and we may 

 commence with a few observations 



Fie 812. Liverwort. Al r rl Fig. 813. Hypnum. 



concerning them. They are an 



extensive family and very beautiful, some of the tropical species being particu- 

 larly noticeable for elegance. We are here mostly concerned with the deve- 

 lopment of the plant. The polypod ferns fructify under the leaves or "fronds," 

 which open from a ball. The seed-cases or sorri are situated at the back 

 of the fronds in browri spots, and when examined they will be found to be 

 collections of capsules like tiny cases. There is -a kind of band at the upper 

 part which at the proper time is extended, and tearing open 

 the capsule releases the seeds. These seeds or "spores" are 

 very minute, and not properly seeds but buds, every one of 

 which can generate seeds. So if we try to grasp 

 in imagination the generating powers of a few 

 fern fronds, we shall miserably fail in the 

 attempt. 



Some ferns have the "spores" upon the 

 summit of the frond. The osmundas belong Fig ' 8 's-Bryum. 

 to this family, and are known to all as the " flowering 

 fern," a contradiction palpable enough under the circumstances. 

 Fig. 814. Horsetail, ^hc beautiful dust upon some ferns has been mistaken for 

 "spores" by many people, but it is merely a natural ornament of the plant. 

 The venation and vernation of ferns are very curious, but in the determina- 

 tion of ferns the only sure way is to consider the sorri and the venation. 



