.‘368 8UMMARY OF CURRENT RESEARCHES RELATING TO 
In Lycoperdon , Geaster , and Bovista the glebe originates in the same 
way, by the formation of cavities in the central portion of the young 
sporophore, and the entrance into these cavities of the apices of hyphse, 
which subsequently swell up into basids. The subsequent development 
varies somewhat in the three genera. In the mature structure, Lycoper- 
don displays the greatest degree of differentiation, the sterile portion of 
the glebe being most fully developed ; in Geaster this is reduced to a small 
column, and in Bovista disappears entirely. The Hymenogastreae may 
be classified under four distinct types, viz. Hymenogaster , Hysterangium 
(including Gauteria ), Bhizopogon, and Melanogaster. Phallus is probably 
derived from Hymenogaster ; Clathrus from Hysterangium ; Bovista , 
Geaster , and Lycoperdon from Bhizopogon. 
Resting-cells of Merulius lachrymans.* — Herr U. Dammer describes 
a peculiar condition of the mycele of this fungus, consisting of short 
deep-brown thick-walled cells, which have apparently a resting function, 
and probably assist materially in the persistence and spread of dry rot. 
Rhizina undulata.j" — Prof. R. Hartig finds that conifers are attacked 
by this parasite only when growing on poor soil. Mycelial structures 
of the nature of a Bhizoctonia spring from the cortex of the root, and 
produce numerous loop-cells. In the mycele are produced minute 
Micrococcus- like bodies which appear to multiply by budding, and to 
play an important part in causing decay. The fructification developes 
in the soil at a distance from the plant attacked. 
Mycetozoa. 
Absorption and Digestion of Organic Substances by the Plasmodes 
of Myxomycetes.j — Dr. L. Celakovsky, jun., gives the results of a 
number of experiments on the powers of absorption and digestion of 
living and dead substances possessed by the plasmodes of various 
Myxomycetes, especially of Chondrioderma difforme. The substances 
employed were : — staminal hairs of Tradescantia, Confervoideae ( (Edo- 
gonium , Conferva , Ulothrix ), Zygnemaceas, Desmidiaceae ( Cosmarium 
hotrytis , Closterium lunulaf Scenedesmus, Pleurococcus , Chlamydomonas , 
Diatomaceas ( Navicula , Nitzschia , Synedra), Flagellata ( Euglena ), 
Ciliata ( Colpoda ), Rhizopoda, Myxomycetes (plasmodes of Chondrioderma , 
Didymium , &c.), Fungi (hyphte, spores of Penicillium , Mucor , Phyco- 
myces , &c.), and bacteria ( Bacillus megaterium , B. suhtilis, &c.). 
In the case of protoplasts enclosed in a cell-wall no change was 
observed for several hours, or even for several days ; such processes as 
the growth of germinating fungus-spores, the streaming of protoplasm 
within the cells of the hairs of Tradescantia, the division within the 
cysts of Colpoda cucullus , &c., went on unchanged. Since these pro- 
cesses are dependent on atmospheric respiration, this shows that there 
must be an excess of oxygen in the protoplasm of the enclosing plasmode. 
In the case of naked motile cells, such as diatoms, Chlamydomonas pulvis- 
culus, &c., the motion was usually at once arrested, whether the object 
were absorbed into the protoplasm or into a vacuole. When fragments 
* Ber. Deutsch. Bot. Gesell., x. (1892) pp. 644-5. 
t Forstlich-naturw. Zeitschr., i. (1892) pp. 291-7 (10 figs.). See Bot. Centralbl., 
liii. (1893) p. 180. f Flora, Ixxvi. (1892) Erg'anzungsband, pp. 182-244. 
