364 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Saprolegniere with sexual, and the Zygomycetes with non-sexual repro- 
duction. In addition to the sporanges, conids now arise, the sporange 
itself becoming a spore ; oidium-forms and chlamydospores are also de- 
veloped. Already in the Zygomycetes the sporanges may either be free, — 
exosporangial forms ; or may be enclosed in an envelope, — carposporan- 
gial forms. The higher fungi, in which there is no sexual reproduction, 
are connected with the Zygomycetes in two series, a series of sporangial 
forms which ends in the Ascomycetes, and a series of conidial forms 
which ends in the Basidiomycetes. The ascus of the former is a spo- 
range ; the basids of the latter are conidiophores. The Mesomycetes 
(Hemiasci and Hemibasidii) are transitional forms between the lower 
Phycomyeetes and the higher Mycomycetes. The whole structure of 
Fungi points to an adaptation to a terrestrial mode of life. 
Red-staining Fungus of Raw Sugar.* — The raw sugar in a factory 
in Silesia was found covered with red lumps about the size of peas or 
hazel-nuts. The authors, Herren A. B. Frank and A. Herzfeld, found 
that these were due to two kinds of organisms, the chief of which was a 
fungus belonging to the Saprolegniacese or Chytridiaceae. The living 
filaments were colourless, but when dead they contained a red pigment. 
The formation of this pigment, which was soluble in water and stained 
the sugar, was attributed to a small bacillus found in large numbers. 
The lumps gave an acid reaction, and if one were thrown into a solu- 
tion of refined sugar, in the course of ten days 10 per cent, of saccharose 
would be changed to invert sugar ; but to which of the micro-organisms 
this result is to be attributed is yet undecided. 
Influence of Parasitic Fungi on the Host-plant, f — Herr J. H. 
Wakker has investigated this subject in regard to the following fungi : 
— Exobasidium Vaccinii on Vaccinium Vitis Idseo , various species of 
JEcidium, Boestelia lacerata on Crataegus, Puccinia suaveolens on Cirsium 
arvense, Xenodochus carbonarius on Sanguisorba officinalis, Cystopus can- 
didus on a number of Cruciferae, Peronospora parasitica on Brassica 
nigra , Exoascus Pruni on Prunus Padus, E. alnitorquus on Alnus glutinosa , 
Urocystis Violae on Viola odorata, U. Maidis on Zea Mais, Plasmodiophora 
Brassicse on roots of Brassica. In respect to their influence on the 
host, he proposes to classify parasitic fungi under the four following 
categories: — Cteinophytes , the influence of which is of a chemical 
nature only ; Hypertrophytes (by far the most numerous category), which 
cause hypertrophy of the tissues ; Isotrophytes, whioh cause only slight 
changes, and whose influence is purely chemical ; and Atrophytes , which 
induce atrophy of important organs. 
The most striking change occasioned by parasitic fungi is the 
decrease of the mechanical tissue or of thickenings of the cell-wall. 
This is manifested in the suppression of the collenchyme, of the scleren- 
chyme, and of the layer of stone-cells, and in the absence of thickening 
and of lignification of the medullary cells. In this, and in other points, 
the phenomena of parasitism coincide with those of etiolation. As 
regards the cell-contents, the formation of chlorophyll and of calcium 
* Zeitschr. d. Vereins f. d. Rlibenzucker-Industrie d. Deutschen Reichs, xli. 
(1891) pp. 662-7. See Centralbl. f. Bakteriol. u. Parasitenk., xii. (1892) pp. 661-2. 
f Jakrb. f. Wise. Bot. (Pringsheim), xxiv. (1892) pp. 499-548 (5 pis.). 
