ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 283 



Germ-theory applied to Fungi parasitic on Plants* — M. Comu 

 considers that M. Pasteur's theory may be applied with advantage to 

 the explanation and treatment of parasitic diseases of plants. He 

 calls attention to the fact that the parasitic fungi of Europe do not 

 generally infest the whole plant, but only certain organs which may 

 be cast off; and that when the fungus is thus cast off with these parts 

 it is for a considerable time at the mercy of the weather ; further, it 

 will produce reproductive germs which again, pending their develop- 

 ment into a new plant, are delivered over to the risks of surrounding 

 conditions. Perpetuation of the species is effected — 1. By persistence 

 of the mycelium, as such, through the winter, to reproduce the species 

 in the spring, as is the case with some Ascomycetes. 2. By production, 

 at the death of the mycelium, of germs fitted to withstand unfavourable 

 conditions, and attacking the plants at the most suitable times, as 

 happens with the Uredinece, Ustilaginece, Peronosjjorece, CJii/tridinece, 

 Mi/xomycetes, and some Ascomycetes. 



These organisms may be thus combatted : — 1. By placing the cast- 

 oif parts of their hosts under such conditions as to destroy the 

 parasites. This may be eifected by drying the leaves, branches, &c. 

 (for the Phacidice, Dothideacece, most Septoriacece, &c.), or by using 

 the leaves as food or litter for cattle, or for cumpost, or (as with 

 Peronosporece, &g.) by more violent means. For example, those parts 

 of the vine which are affected by O'ldium or by anthracnose should be 

 removed, and the twigs of that year's growth should be washed with 

 compounds of sulphur, such as the sulpho-carbonates ; this method 

 destroys at the same time the winter eggs of the Phylloxera and Pyralis. 

 When Peronospora viticola is present, the leaves and detached twigs 

 should be bm-ned ; the ashes may be used as manure. 



Composition of the Protoplasm of ^thalinm septicum.f — 

 J. Eeinke enumerates a long list of substances as immediate con- 

 stituents of the naked protoplasm of the fructification of ^thalium 

 septicum. The plastin forms a swollen plastic continuous framework 

 iu the interior of the plasmodia, as well as the firmer pellicle on their 

 surface, and can be separated by pressure from the fluid portions of 

 the protoplasm. The albuminoids amount to scarcely 30 per cent, of 

 the dry substance. This appears to dispose of the theory that proto- 

 plasm consists merely of albumen. From a chemical point of view 

 the protoplasm even of the lowest organisms is a highly complicated 

 structure. Among the non-organic constituents of the protoplasm 

 imder investigation are ammonium carbonate, calcium carbonate, 

 phosphate, and sulphate, magnesium (probably phosphate), potassium 

 phosphate, sodium chloride, and iron ; there were also found calcium 

 stearate, palmitate, oleate, lactate, oxalate, acetate, and formiate, as 

 well as a large number of organic substances. 



Intrusion of a Fungus into the Pulmonary Tissue during Peri- 

 pneumonia.;!: — \Yhile withholding his judgment as to the cause of 



* Comptes Rendus, xci. (ISSO) p. 960. 



t Eeiuke. J., " Ueber die Zusammenaetzuug des Protoplaama vou ^thaiium 

 septicum." See Bot. Ztg., xxxviii. (1880) p. 815. 

 I Comptes Eendus, xcii. (1881) pp. 254-6. 



