-96- 



which is there replaced by various species of Thrinax. Anemia 

 adiantifolia, more suggestive in appearance of a Botrychium than 

 an Adiantum, is not uncommon on dry barrens throughout the 

 keys, but it occurs in the greatest abundance around Miami. 

 Tcenitis lanceolata has been collected on Old Rhodes Key, which 

 we found no opportunity to visit. Blechnum seri'ulatum and 

 Psiloticm probably also occur on the islands, or at least on the 

 adjacent mainland; so far as I am aware, however, there are no 

 other representatives of the Pteridophyta in this region. Lyco- 

 fiodium and Selaginella are conspicuous by their absence. 



Of the species which we personally collected, four were 

 epiphytic and six terrestrial, the large proportion of the former 

 indicating the approach to tropical conditions which these islands 

 afford. 



Washington, D. C. 



SOME VARIATIONS IN THE ADDER'S-TONGUE. 



By William R. Maxon. 



BY WAY of supplementing Mr. A. A. Eaton's interesting note 

 entitled '-Two Odd Ophioglossums," which appeared in 

 The Fern Bullltin for January, 1897, I desire to call 

 attention to two further examples of variation in the fruiting 

 spike of Adder' s-tongue. As in the second of Mr. Eaton's plants, 

 my first specimen has the upper half of the fertile spike entirely 

 sterile and leaf-like, the basal portion bearing several apparently 

 normal sporangia, seven on one side and five on the other (Fig. 

 a). The spike is about three -fourths of an inch long, rather un- 

 dersized for the size of the plant. The unusual form is, as Mr. 

 Eaton suggested in the case of his specimens, undoubtedly an 

 instance of reversion ; and it may be taken to 

 indicate somewhat imperfectly a former stage * 

 in the evolution of the plant, when the speciali- \A 

 zation of the fertile parts had not been carried tfi 

 to the extent which we observe to-day in the 3 

 almost complete elimination of the foliage feat- w 

 ure in the normal fruiting spike. 



The second case of variation is that of sim- 

 ple furcation of the fertile spike near its tip. 

 This is a phenomenon which, by numerous ob- 

 •9-* servations published from time to time in The* 



