166 BOTANICAL GAZETTE [AUGUST 
the chromosomes in this mitosis move independently of any spindle.—C. J. 
CHAMBERLAIN. 
Studies in ferns.—Apogamy in Cystopteris fragilis, hybridization in A sple- 
nium, and conditions of heredity in certain ferns, have been investigated by 
A. HEILBRONN.” The group last considered includes, as true varieties, the 
following: Aspidium Filix-mas var. grandiceps, A. aculeatum var. cruciato- 
polydactylum, Athyrium Filix-femina var. corymbiferum, A. Filix-femina var. 
multifidum, A. Filix-femina f. multifidum Mapple-Beckii, A. Filix-femina var. 
laciniatum and var. purpureum Lowe. Others not considered true varieties are 
Athyrium Filix-femina var. Fieldiae Moore, A. Filix-femina {. multifidum 
minus, and -Aspidium angulare {. grandidens. The general conclusions of the 
author are: (1) Cystopteris fragilis {. polyapogama develops prothallia which 
show the power of developing sporophytes from unfertilized egg cells or by 
vegetative apogamy, the two cases sometimes being side by side; (2) the 
question as to whether Asplenium germanicum is a hybrid between two forms 
is not yet settled, but by crossing Asplenium septentrionale (female) and A. 
Ruta-muraria (male), a plant was obtained which stands nearer to A. ger- 
manicum than any other known form; (3) some fern-forms which had not 
been investigated before appear apogamous. Of the different forms of Athy- 
_ rium Filix-femina from England, some are true varieties and some revert. 
Attempts to obtain forkings artificially were unsuccessful—Norma E. 
PFEIFFER 
Water-cultures of fern prothallia.—In a short paper H. FiscHER” gives 
some of his results with the germination of fern spores, in obtaining material 
for his work on variation, hybridization, etc. He states the advantages of 
water-cultures over solid substrata as being threefold: the chemical constitu- 
tion can be regulated; the cultures are cleaner, and material is fit for micro- 
tome sections without extra care; the spores may be sowed as thick as desir- 
able, and easily diluted, like a solution, if too close together on germination. 
The danger lies in the drying out of cultures, or too great evaporation, resulting 
in plasmolysis. A second danger lies in the production of abnormal forms by 
Arthur Meyer’s ict, the formula of which he gives. He finds that changing 
one compound or its concentration, changing the reaction of a solution, etc., 
often produce the desired germination. But evidently there is no general 
rule for this, as there is none for the length of time after ripening that a spore 
will germinate. In Asplenium Serra, herbarium material germinated after 
48 years. In some few cases the author is as yet unable to induce germina- 
tion.—NorMaA E, PFEIFFER. 
9 HEILBRONN, ALFRED, Apogamie, Bastardierung, und Erblichkeitsverhiltnisse 
bei einigen Farnen. Flora (n.s.) 1: 1-42. figs. 43. 1910. 
20 FiscHER, Huco, Wasserkulturen von Farnprothallien, mit Bemerkungen tiber 
die Bedingungen der Sporenkeimung. Beih. Bot. Centralbl. 27':54-59. 1911 
