312 The Botanical Gazette. [August, 
siderable incrustation of iron. Among the mosses, Fonti- 
nalis antipyretica LL. gave a very intense reaction, but onlyin 
the walls; the cell-contents never gave evidence of amy 
amount of iron being present. In the procambium of the — 
cotyledons of Szzapzs alba, the author had a well marked re 
action; during the first or second week of germination the 
iron disappears entirely. 
Following this is a very important series of investigations — 
on the ‘‘iron-bacteria:” Crenothrix Kiihniana Rabenh.®, Crem — 
othrix dichotoma Cohn, and Leptothrix ochracea Kiitz., pi — 
viously studied by Cohn®, Zopf7, and Hugo de Vries* with 
regard to their iron-hoarding properties, and first noticed Ia — 
this connection by Winogradsky;® Molisch finds that the iron — 
even after its oxidation in the ‘‘Gallerthiille” of these alge, — 
never enters into their protoplasm. The outer slimy layet 
has a very singular attraction for the iron contained in the nu- ‘ 
tritive solution which there becomes oxidized. But the other 
parts of these plants have no specific oxidizing power. 
he author fur 
Studies on chlorosis showed that deficiency of iron oS 
protoplasm of any plant which may be subject to an 4 
causes a general pathologic state of the plant, and that @ 
condition named is only one feature thereof. — This, it . 
Fifty-five species of fungi gave iron-reaction. rag a 
connection with experiments in nutritive media, led se 5 
sult that at least for Aspergillus niger iron 18 indispe : 
and that this substance seems to play a very importan 
in the life of many other fungi.—J. CHRISTIAN Bay. 
Latent irritability. oe 
Sachs!°, referring to his very extensive studies : ee 2 
ropism, calls attention to a special side of root ae pet 
cal and other epiphytes, namely to the fact that ¢ 
hairs are not geotropic, but follow other laws in 
5=Cl. polyspora Cohn. 
®Cohn’s Beitrage 1. 108. ; were 
_ 7Entwicklungsgeschichtliche Untersuchung tiber Crenothrix poly al a 
lin, 1879 ee wast 
Satod Pflanzen und Thiere in den dunklen Raumen de 
tung. 7 1890, : 
Ueber Eisenbacterien. Botanische Zeitung. 1888, bere (Flora. at! 
1°Physiologische Notizen. V. Ueber latente Reiz : 
(1893). 1-15. : 
