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SUMMARY OF CURRENT RESEARCHES RELATING TO 
centage, be favourable to tbe growth and multiplication of tbe yeast; 
for 10 and even 15 per cent, was found not to be deleterious. Besides 
this insensitiveness to the presence of salt, even in large quantity, this 
organism also possesses an unusual resistance to conditions extremely 
unfavourable to vegetation, such as exclusion of air, concentration of the 
medium, or the presence therein of alcohol or acetic acid. The exact 
source of the yeast is undetermined, though a marine origin is the most 
probable. 
Morphology of Blastomycetes.* — In his researches on the mor- 
phology of Blastomycetes Dr. O. Casagrandi discusses at some length 
the membrane and the granules. The membrane is declared to be not 
a simple structure, but composed of two or more layers, both in the old 
and young ferments. Chemically the membrane is closely allied to 
pectin, and its principal characteristics are that it does not give the 
cellulose reaction with iodine ; it is soluble in strong chromic and sul- 
phuric acids ; is insoluble in Schweizer’s reagent, even if previously 
treated with hydrochloric acid, alcohol, or 2 per cent, acetic acid ; and 
is only stained with difficulty by carminic or anilin dye solutions. 
The granules are represented as protoplasmic vesicles filled with a fatty 
substance which, according to the age of the cell, is liquid or solid. 
While these granules exhibit microchemical reactions proper to fatty 
substances, they also give some of the reactions indicative of proteid or 
nuclein. The latter are stated to be due to the investment, the former 
to the contents. With regard to the nucleus, the author expresses his 
certain belief in its existence. 
Myxomycetes. 
Pseudocommis Vitis.f —This Myxomycete, detected by M. Debray 
in the leaves of diseased potatoes, has now been observed by M. E. Roze 
in the hypodermal cells of the tubers, in the form both of plasmoaes and 
of cysts. It attacks both the nucleus and the starch-grains. The author 
finds its occurrence very common in garden and greenhouse plants. The 
black and brown spots that indicate the malady known by gardeners as 
“ burning ” are due to the attacks of this parasite. It is often over- 
looked, owing to its very rudimentary structure, consisting of plasmode- 
like mucus, which becomes encysted in certain conditions. As long as 
this plasmode is in a living condition, it is able to escape, under favour- 
able conditions, and infect other vegetable tissues. 
The author further records the presence of this parasite in the leaves 
of Elodea canadensis , in the marine flowering plants Zostera and Bujppia, 
and in Fucus serratus and vesiculosus. 
Protophyta. 
o. Schizophycese. 
Protophyta of the Norwegian Nordhavs Expedition, 1876-784 — 
Herr H. H. Gran’s contribution to this publication includes the Diato- 
* II Naturalista Siciliano, ii. (1897) pp. 1-24. 
t Comptes Rendus, exxiv. (1897) pp. 704-5, 1109-11, 1470-2; exxv. (1897), 
pp. 362-63, 410-11. Cf. this Journal, 1896, p. 215. 
X Christiania, 1897, 36 pp. and 4 pis. (Danish and English). 
