18 
Var. frondosci is an abnormal form in which th e fertile frond 
takes on some of the characters of the sterile, such fronds being 
furnished below with one or more pairs of foliaceous pinna?. Some 
fronds of this sort are three feet or more long with 8 or 10 inches 
of fertile pinnae and 10 or 12 pairs which are sterile. 
Another form has several pairs or more of fertile pinnae below, 
while the upper part is that of a normally sterile frond. Rarely we 
find a normally sterile frond with two oi-three of the intermediate 
pairs fertile, thus mimicking the fertile frond of O. Claytoniana. 
These abnormal fronds of 0. cinnamomea occur most abundant- 
ly on ground which has been burned over, the ferns continuing to 
produce them for several years They are for the most part later 
than the ordinary fertile fronds and should be looked for about the 
10th of June. 
LITERATURE. 
A LARGE number of books relating to ferns have been pub 
lished, some of them very expensive. To the beginner, who 
wishes for illustrations, and books easily accessible, can be 
recommended “A Fern Book for Everybody,” by M. C. Cooke, (Eng- 
lish,) ; and Edward Knobel’s “The Ferns and Evergreens of New 
England.” The latter contains outline figures of the more common 
species in Filices, Ophioglossacese and Lycopodiaceae, including, 
however, a few which are probably not within the limits assigned. 
To these may be added Prof. Eaton’s ferns of the Northern Unit- 
ed States in the 6th edition of Gray’s Manual, and Prof. Under- 
wood’s /£ Our Native Ferns and Their Allies,” the latter giving de- 
scription of all the American species of Pteridophy ta north of Mex- 
ico. Prof. Eaton’s “Ferns of North America” contains colored 
