432 
Rem.—A less developed form of the preceding but easily 
separated from it by its smaller size, pluripapillate leaf-cells, 
shorter pedicel, shorter and broader capsule and imperfect cilia. 
The leaves are usually not so abruptly contracted above the base, 
broadly ovate-lanceolate, the margins not rugose. 
Comparisons kindly made by Mr. Gepp, of the British Museum, 
verify the statement of Renauld & Cardot * as to the identity of 
Hypnum ramulosum Upe. and H. crispifolium Hook., the types of 
both being unipapillate. The type of Leskea /axifolia Hook. (/. 
laxifolium Schwaeg.), loaned Mrs. Britton by the authorities at 
Kew, is Brachythecium reflexum (W. & M.) Br. & Sch. 
Rosemont, N, J. 
Mesophyl of Ferns. 
By Mary Etcin Gtoss. 
While making a comparative study of the chlorophyl bearing 
cells of plants, including ferns, I noticed what appeared to me to 
be a marked resemblance between the sections of the leaves of two 
species of Adiantum. As some species of Nephrolepis, Dryopteris, 
and Polypodium show also peculiarities of structure characteristic 
of each genus, I have tabulated the results of observations made 
from February to May, 1897. 
A study of the mesophy]l of ferns made from material from the 
greenhouses near Evanston, and from the Missouri Botanical 
Garden, affords some characteristic differences and resemblances. 
In the species studied these seem to givea means of distinguishing 
one genus from another, as the presence of chlorophyl in the 
epidermis, the form and arrangement of the cells of the mesophyl, 
the size of the air spaces, the number of cells in thickness of the 
mesophyl, the presence of palisade tissue, and the number of cells 
in its depth, seem to be constant through a genus. 
Species were examined from the following genera: Adiantum, 
Dryopteris, Asplenium, Nephrodium, Nephrolepis, Polypodium, Pteris, 
Scolopendrium, and Blechnum. The sections were cut perpen- 
dicular to the smaller veins of the fresh frond, and the comparison 
* Muse. Am, Sept. 50. 1892, 
