72 BOTANICAL GAZETTE [JANUARY 
beech-maple forests of the Chicago region. Thus it is possible to make rather 
accurate comparisons of the conditions within the forests of the east and the 
west and to obtain quantitative demonstration of the equal mesophytism of 
the latter. 
The differences in the evaporating power of the air in the different associa- 
tions are found to be quite’sufficient to show that this factor must be an impor- 
tant one in causing succession. Such accumulations of quantitative data as 
are contained in the present paper mark the advance of ecology along lines tend- 
ing toward greater t ,and it is to be hoped that the will become increas- 
ingly numerous.—GeEo. D. FULLER. 
Phylogeny of Filicales.—In continuing his studies of the Filicales, 
Bower” has investigated Blechnum and its allies, and finds that the char- 
acters of the sori are of most importance in suggesting phylogenetic lines. 
The genus is treated in its wider sense, as comprising the subgenera Lomaria, 
Salpichlaena, and Eu-Blechnum. In Lomaria the indusium appears marginal, 
while in Eu-Blechnum it becomes cena latremas iia owing to the 
formation of a new structure which Bower calls the “‘flange.’’ He produces 
evidence from a comparison of the eievelbacical in numerous species that the 
protective organ is phyletically the same throughout the genus Blechnum, and 
he calls it the “‘phyletic margin.” The general conclusions reached are as 
ollow 
The Blechnum-like ferns and their derivatives represent a true phyletic 
sequence, which is traced to the region of the Cyatheaceae, the actual point 
of contact probably being Matteuccia intermedia, a fern of North China recently 
described by CHRISTENSEN. From this source several divergent lines have 
proceeded, the main line leading through § Lomaria to Eu-Blechnum, involving 
the origin of the “flange” and the diversion of the ‘“phyletic margin” to 
indusial functions. Minor lines led to Acrostichum-like derivatives in Steno- 
chlaena and Brainea. Interruption of the fusion sorus, occurring as an anomaly 
in Blechnum, led to the conditions shown in Woodwardia and Doodia. An 
outward arching of the fusion sorus of Blechnum, ultimately combined with 
interruption, gives the key to the origin of Scolopendrium. An outward swing- 
ing of the interrupted fusion sori, variously combined with archings and new 
formations of partial sori, and various branchings of the leaf, give the several 
types of Asplenium. The relation of Plagiogyria to the whole series is regarded 
as problematical, but it is suggested that it is an isolated and relatively primi- 
tive genus.—J. M. C 
Evolution of inflorescence.—PaRkIN® has studied inflorescence from the 
evolutionary point of view, a subject which in his judgment has been “strangely 
* Bower, F. O., Studies in the phylogeny of the Filicales. IV. Blechnum and 
allied genera. Ann. Botany 28 : 363-431. pls. 22-32. figs. 1914 
ARKIN, J., The evolution of the inflorescence. Sie. Linn. Soc. Bot. 42: 
511-563. 1914. 
