322 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
gators during tlie past eight years are probably yeast-fungi. The second 
is that yeast-fungi have been found in man and in lower animals affected 
with malignant tumours. These, when isolated, grown on nutrient 
media, and, when inoculated into other animals, gave rise to malignant 
tumours which showed the same characteristics as the original tumours. 
Origin of Lichens.* * * § — Mr. F. Clements criticises very unfavourably 
Reiuke’s view that Lichens must be regarded as a distinct class of 
Cryptogams, independent of the Fungi. They may, he considers, be 
traced back in all cases to distinct Fungus-ancestors. The Ascolichenes, 
to which the great majority belong, were derived from the Ascomycetes 
at an earlier period than the Hymen olichenes from the Hymenomycetes. 
Their great specialisation and the interval of time that has elapsed, 
have, however, to a considerable extent, obscured the points of de- 
parture. 
Pertusariese.f — Herr 0. Y. Darbishire gives a monograph of the 
German species of this family of lichens, 31 in number, belonging to 
7 genera, viz. : — Pertusaria, Pionospora, Ochrolechict, Vciriolarici, Mega- 
lospora, Varicellaria, and Phlyctis. He then enters into a full descrip- 
tion of various points in their anatomical structure, especially the 
formation of the soredes and of the apotheces. In Variolaria and 
Oclirolechia , and probably also in all the other genera, the sorales, or 
clusters of soredes, appear to be metamorphosed apotheces. 
Structure of Agaricus (Pleurotus) ostreatus.J — M. L. Matruchot 
has followed out the development of this fungus in various media, with 
the following results : — There are three different modes of fructification : 
— by budding carpophores ; the cauliflower fructification ; and the 
coralloid fructification. The cystids appear to be deformed basids. 
The normal basids, the hymenial cystids with 1, 2, or 3 sterigmas, the 
extra-hymenial cystids or pseudo-conids, and probably also the normal 
conids, must be regarded as differentiations from a single elementary type. 
Calostoma.§— Mr. C. E. Burnap gives a review of the American 
species of this genus of Gasteromycetes, and sums up in favour of its 
affinity with Tulostoma rather than with Geastei\ In both Calostoma 
and Tulostoma the spores are borne laterally on the basids, which is not 
the case with Geaster , nor w ith any other genus of Gasteromycetes. 
Presence of an Oidium in Pseudo-lupus vulgaris.il — Mr. T. C. 
Gilchrist and Mr. W. R. Stokes report the discovery of an oidium in 
the diseased tissue taken from a case of pseudo-lupus of eleven years 
duration. Sections showed hypertrophy of the epidermis, abscesses, 
and, in the deeper parts of the corium, tuberculoid nodules. In the 
abscesses round and oval cells 10-20 /x in diameter were observed. 
Many of these cells showed buds, a doubly contoured membrane, and 
occasionally vacuoles. Very few giant cells were noticed. From the 
pus was cultivated, on glycerin-agar and on potato, an oidium, having at 
* Amer. Naturalist, xxxi. (1897) pp. 277-84. Cf. this Journal, 1895, p. 82. 
t Engler’s Bot. Jahrb., xxii. (1897) pp. 593-671 (39 figs.). 
X Rev. Gen. de Bot, (Bonnier), ix. (1897) pp. 81-102 (1 pi. and 19 figs.). 
§ Bot. Gazette, xxiii. (1897) pp. 180-92 (1 pi.). 
|| Bull. Johns Honkins Hosp., vii. No. 64. See Centralbl. Bakt. u. Par., l te Abt., 
xxi. (1897) pp. 692-4! 
