34 



THE FERN BULLETIN 



The loss in the original fern-flora is sligfhf in this re- 

 gard when compared with that of flowering plants. 

 As nearly all of the state is in the region of the glacial 

 drift, the soil is influenced by this condition also. The 

 ravines cut in the drift and in the underlying rock 

 where it is reached, with their varying degrees of 

 moisture and shade, show the greatest variety in fern- 

 life, though a greater abundance of certain kinds may 

 be found in woods and swamps. The prevailing rocks 

 are limestone, but sandstones occur in some localities, 

 especially along the Illinois and Rock rivers. These 

 in some parts of the state, particularly in the coal 

 measures, the area of which is large, may be inter- 

 stratified with shales and slate. These rocks and the 

 soils resulting from their disintegration and decomposi- 

 tion, taken in connection with those of the glacial drift, 

 provide a fair range of edaphic conditions for the 

 growth of ferns. It is evident that such as prefer a 

 calcareous soil will be best represented, if any prefer- 

 ence of this kind inheres in their nature. 



It will be seen from the list that not quite one half 

 ( 56) of the Pteridophytes accorded specific rank in 

 "Gray's New Manual of Botany" (115) are reported 

 from this state. The genera are represented in larger 

 proportion, 23 of the 31 given, or if Athyrium be separ- 

 ated, 24 of 32, or three-fourths of them. All the spe- 

 cies of several of the smaller genera are found, up to 

 three in the case of Osmunda, but all of none with 

 species exceeding this number. The genus most fully 

 represented is Equisctum, eight of the ten, or nine of 

 eleven when E. robustum is given specific rank. To 

 these must be added E. Fcrrissii, not in the Manual. 



Reliable data for the distribution of the ferns of the 

 state are not very full. It is hoped that they may be 

 made more complete by the co-operation of those into 



