CLASSIFICATION OF FERNS. 27 



twenty-nine tribes, arranged according to natural 

 characteristics, and broken up into two hundred 

 and twenty genera. Although this arrangement 

 is very little in use, the division of species in it is 

 much more equal and less artificial than the other 

 system, and is to be strongly commended. Mr. 

 Smith's long service at Kew Gardens, where he 

 had under his care and constant observation some- 

 times a thousand species of ferns, and where he 

 had the use of the largest herbarium of ferns in 

 the world, gives his opinion great weight. 



Sachs, complaining of the artificial manner in 

 which the Filices are divided by various authors, 

 proposes a classification in which the Hymenophyl- 

 lacece (Filmy Ferns and Bristle Ferns) shall be 

 placed at the bottom, instead of the middle of the 

 list as with most authors, because these are ferns 

 peculiar for their small size and thin fronds, and 

 are more nearly related to the mosses than are other 

 ferns. His orders are, 



1. Hymenophyllaceae. 4. Osmundaceae. 



2. Gleicheniaceae. 5. Cyatheaceae. 



3. Schizaeaceae. 6. Polypodiaceae. 



Marattiacece, included in Hooker's classification, 

 he says should, on account of the formation of its 

 fruit, be placed beside the Equisetacecs and the 

 Ophioglossacecz. 



We have now learned what place ferns occupy 

 in a general classification of plants, and how they 



