NATURE STUDY 
PUBLISHED UNDER THE AUSPICES OF THE 
Manchester Institute of Arts and Sciences. 
Vol. I. March, 1901. No. 10. 
Ferns and Fern Allies. VI. 
BY FREDERICK W. BATCHEEDER. 
As was stated in the first article in this series, (See Vol. 
i, No. 5.) all the local ferns may be considered as belong¬ 
ing to three families, of which the typical genera are Oph- 
ioglossum, Osmunda and Polypodium. The order in which 
the names are given also indicates the order of natural de¬ 
velopment, the first family containing the most ancient and 
least specialized forms, the third, the most modern and 
highly specialized forms, while the second constitutes a 
connecting link, but recently recognized, between the other 
two. This second family is not so much a bridge as the re¬ 
mains of a bridge over the chasm between the so-called “eu- 
sporangiate” and the “lepto-sporangiate” ferns, between 
those in which the sporangia are formed from the interior 
tissue of the leaf and those in which they are derived from 
a single epidermal cell. Doubtless many other intermediate 
forms have perished and left no sign. 
Attention was called in the last article to the enormous dis- 
