72 BOTANICAL GAZETTE [ony 
It is to be regretted that fuller credit for most of the apparently new ideas 
is not assigned. One looks in vain for acknowledgment of the works of FrvH 
and ScHROTER, GANONG, and TRANSEAU, whose studies have partially covered — 
the significant results of Davis. The mention of these works in their proper 
places would relieve the book of much that might appear to be an original 
contribution. The greatest value of the book to the ecologist lies in its careful 
descriptions of various types of swamps and the detailed record of the distribution 
of peat-forming species. A complete index makes this material readily available. 
—LeRoy H. Harvey. 
Endodermis of ferns.—The sporadic occurrence of the endodermis and the 
modifications it shows have been frequently remarked. A comprehensive study 
of this layer in the fern stem and leaf has been made by BASECKE,?? whose contri- 
bution may be considered a companion paper to that of Rumpr° on the fern root. 
Following this writer, BASECKE distinguishes (1) the primary endodermis, — 
characterized by Caspary’s band, and (2) the secondary endodermis, in which 
the cell walls are more or less thickened and suberized. The leaves of the euspo- 
rangiate ferns lack an endodermis, while those of Osmundaceae show only @ 
primary layer; but most of the leptosporangiate ferns are well provided through- 
out the length of the leaf with a secondary layer. Anatomical and physiological 
studies show that food manufactured in a fertile leaf first supplies the sporangia, 
and any excess passes out through the vascular bundles. In rhizomes devoted 
to storage, only a primary endodermis is found, and in those which are active 
in propagating the plant a more or less impenetrable layer extends nearly to the ra 
growing point; hence the view is maintained that the secondary endodermis _ 
serves to prevent the escape of food from the vascular bundles while it is in process 
of transport. ie 
The second part of the paper describes a reinvestigation of the question as - 
the occurrence of cork in the ferns, and the conclusion is reached that true 
is never present, but that substitutes are frequent, such as ‘‘metacutinized” aS — 
of the outer cell layers. In this respect the ferns are less differentiated than the 
angiosperms. As to shedding of leaves, the author distinguishes three sorts of 
absciss layers, in contrast to earlier workers who were unable to find special i 
structures connected with leaf fall, A classification of the various m en a 
tissues of ferns concludes the paper.—M. A. CHRYSLER. 
Protection from light.—BaumErt reviews very fully3t the many ee 
that appear in literature as to the function of various structures in protecting 
29 BASECKE, Paut, Bietrage zur Kenntniss der physiologischen Scheiden - es 
Achsen und Wedel der Filicinen, sowie iiber den Ersatz des Korkes bei dieseT Pian be 
zengruppe. Bot. Zeit. 66:25-87. pls. 2-4. 1908. ae 
__%° Rumer, G., Rhizodermis, Hypodermis, und Endodermis der Farmwurill: 
Bibl. Botan. 62: 1904. 
= Baumert, K., Experimentelle Untersuchungen iiber Lichtschutzeinrichtt 
an griinen Blattern. Beitr. Biol. Pfl. 9:83-162. figs. 6. 1907. 
