Their value in determining generic affinities. 163 



least revising a classification which is honeycombed with contradic- 

 tions ? 



As a contribution to this revision, and as in, some sort, an argu- 

 ment for its necessity, the following results of the examination of 

 many hundreds of species and some scores of genera are now sub- 

 mitted. I regret that the limits of my opportunity preclude any 

 claim to completeness in the investigation. 



Advantage has been taken of the process of double staining to 

 make the sections as distinct as possible. 



Diversified as are - the Hieroglyphs in the various species, they 

 are all susceptible of distribution into about four groups. 



1. Punctiform. Fibro-vascular bundles in isolated dots. 



2. Sigmatic. Fibro-vascular bundles collected in two S-shaped 



canals. 



3. Sinuous. Fibro-vascular bundles collected in a zigzag intra- 



marginal canal. 



4. Medullary. Fibro-vascular bundles within a central canal — 



occupying the place of a medulla. 



Of the first of these, Poly podium may be taken as the type ; of 

 the second, Athyrium; of the third, Dicksonia ; of the fourth, 

 Gleichenia. 



More exactly, however, 12 groups present themselves. 



1. Punctiform. Irregular. Bundles in scattered dots. Poly- 



podium vulgare. 



2. Punctiform. Symmetrical. Bundles arranged as in the nails 



of a horseshoe. Two at the base larger. Drynaria. 



3. Sigmatic. Bundles collected within walls of Sclerenchyma 



forming two S-shaped figures like those in the sounding- 

 board of a violin. Athyrium. 



4. Sigmatic -arcuate. S-shaped figures anastomising at the 



upper ends so forming a single arcuate figure. Microlepia. 



N.B. — Though 3 and 4 are often distinct throughout the stipes, 

 both forms are to be found in many individual plants, notably in the 

 so-called Poly podium trichodes, which upon this evidence would be 

 separated from Polypodium. 



5. Aureate. Hieroglyph a symmetrical ear-shaped arch with ter- 



minal incurved lobes. Osmunda. 



