﻿THE FAMILIES OF FERN-LIKE PLANTS. 



Many botanists divide the plant world into four 

 groups, the Thallophytes, Bryophytes, Pteridophytes 

 and Spermatophytes which include respectively the 

 algae and fungi, the mosses and liver-worts, the ferns 

 and fern allies, and the conifers and flowering plants. 

 So greatly do the plants differ, however, that this ar- 

 rangement is becoming more and more unsatisfactory 

 and various rearrangements have been suggested. In 

 "University Studies" for October, 1907, Prof. Charles 

 E. Bessey of the University of Nebraska offers a plan 

 in which, instead of the four divisions, fifteen are pro- 

 posed. Whatever objection may be brought against the 

 new arrangement, it is certain that it comes more 

 nearly representing the correct relationships of the 

 plants than those now in use. Since the fern and fern 

 allies are the living representatives of those plants 

 which have bridged the gap between the lower spore- 

 plants and the flowering plants, we append Prof. 

 Bessey's arrangement of the entire group both living 

 and fossil, slightly abridged as to descriptions begin- 

 ning with the ninth division or phylum which is the 

 one next higher than the mosses. The unfamiliar tech- 

 nical terms in the descriptions of the orders will be 

 made clearer by a re-reading of the article "But Half 

 a Fern" in the January number of this magazine. 



Phylum IX. PTERIDOPHYTA. The Ferns. 



Chlorophyll-green, mostly terrestrial plants, exhibit- 

 ing two generations in each life cycle, viz: (1) the 

 gametophyte, which is small and short-lived, and (2) 

 the sporophyte which is large with roots, stems and 

 leaves and long-lived. 



70 



