42 THE AMERICAN BOTANIST 



That modern plants have descended from ancient and 

 simpler ones is held by practically all biologists, though the 

 exact, or even the approximate, lines by which they have des- 

 cended are still hidden in obscurity. In an attempt to throw- 

 more light on the whole problem of descent, Professor F. 

 O. Bower of the University of Glasgow, has made a most 

 comprehensive inquiry into the morphology and phylogeny 

 of the fernworts, the results of which are to be published 

 in a two-volume work on "The Fern." The group selected 

 for investigation offers an attractive field for study since the 

 forms are easy to distinguish from other groups, are abund- 

 ant and widely distributed, and have a rich series of fossil 

 remains by which they may be traced back to the ancient 

 times. Professor .Bower believes that if the primitive type, 

 from which all the others have descended, can be singled 

 out, it may contribute important data bearing on the descent of 

 land plants in general. In order to visualize this primitive 

 fernwort, each separate character of, ferns is examined in 

 detail to decide what are, and what are not, primitive char- 

 acteristics. A general idea of what the primitive progeni- 

 tor must have been like is then obtained by uniting these 

 characters into a single hypothetical individual. The fea- 

 tures taken for extensive study are the morphology of root 

 and shoot, the vascular system, the structure of the leaf, the 

 dermal and other non-vascular tissues, spore-production, the 

 gametophyte and the embryo. From a consideration of these 

 the author concludes that the simplest fern plant was "a 

 simple, upright, radial, rootless shoot, either unbranched or 

 showing dichotomy." The primitive fern leaf is regarded 

 as being long-stalked with a distal dichotomy of narrow, 

 separate simple-veined segments and the reproductive parts 

 as large solitary spore-cases containing many spores. Com- 



