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veinlets free, branching 2-4 (usually 3) times, the first branch 

 bearing at its enlarged extremity a single bright-brown sorus; 

 the sori thus borne in two rows of 9-17 pairs, one on either side 

 of the midvein at half the distance to the margin. 



The original brief description of Franchet and Savatier may 

 be translated as follows: "The Polypodium vulgare of Japan, 

 as we have seen it, is much smaller than the specimens of 

 Europe ; the pinnae are more remote, narrower, and often more 

 pointed ; the spores are yellowish, rugose, and very finely 

 muricate." The extremely narrow pinnae and presence of the 

 peculiar hair-like chaff serve readily to distinguish the species. 

 Many of the fronds exhibit a marked tendency to coil, the pinnae 

 remaining flat, but the rachis making one or even two sidewise 

 revolutions. The result is very curious. I have seen nothing 

 exactly comparable to it, although the authors mention a 

 similar peculiarity in P. Nipponicum, another Japanese species. P. 

 Japonicum is said to occur throughout the Empire. 



Washington, D. C. 



THE GENUS EQUISETUM IN NORTH AMERICA. 



By Aevah A. Eaton. 



TENTH PAPER. 

 Varieties oe E. utorale. 

 Although so diverse in appearance there are no well charac- 

 terized varieties as that term is generally understood, all forms 

 being readily accounted for by environment alone, and may be 

 produced from one root-stock. In order to present a clear idea of 

 the species, however, it is necessary to give definite descriptions 

 of the extremes of appearance. The gaps can usually be filled, 

 where it is abundant, with a complete set of intergrades. The 

 illustrations of this species have been selected with a view of 

 showing the connecting links, both between varieties and related 

 species. 



1. Humile Milde. Stem stout, 12-14 angled, decumbent at 

 base, then ascending or erect, branchless, or basal internodes, 

 bearing a few stem-like branches, or with scattered or verticillate 



