632 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
brownian movement, and having a strong tendency to agglomerate, and 
multiplying endogenously or by budding. The spores, spherules, conids, 
and hyphae present staining reactions and biological characters identical 
with those of the human parasite. 
Inoculation of trees with cultures of the human parasite resulted 
in a “ canker ” in all respects resembling that produced by Nectria ; 
and conversely, the ingestion of rabbits by cultures of Nectria caused 
the production, in about three months, of round ulcers in the stomach, 
similar to those produced by the ingestion of cultures of the human 
parasite. 
Sphaeronema.* — M. A. de Jaczewski gives a monograph (in French) 
of this genus of Ascomycetes, of which he makes 72 species (two of them 
new), arranged under two divisions, the pseudoparenchymatous and the 
prosenchymatous, rejecting a large numbnr as belonging to other genera or 
as insufficiently known, six others are assigned to a new genus Pseudo- 
yraphium , with the following diagnosis : — Forming brown vertical masses 
oomjiosed of agglutinated hyphae which separate at the apex in a tuft, 
and put out, laterally and in the interior of the bundle, conids which 
usually form a more or less distinct cluster. 
Systematic Position of Microsporum.! — MM. L. Matruchot and 
0. Dassonville have already! demonstrated that Trichophyton aud Achorion 
should be placed in the Ascomycetes among the Gymnoasci. They now 
apply the same arguments to Microsporum. The conidial apparatus is 
of the same type as those of Gymnoascus , Ctenomyces , and Trichophyton. 
The spores are solitary and grow laterally and irregularly on the filaments. 
They are formed by transport and encysting of the protoplasm, and are 
attached by a more or less broad surface. Another argument is furnished 
by the presence of pectinaceous hvphse, similar to those of Ctenomyces. 
Whether Microsporum should be retained as a distinct genus, or sunk, 
witli Ctenomyces , Trichophyton , and Achorion , in Gymnoascus , the authors 
leave an open question. 
Fertilisation of Tuber.§ — Prof. A. N. Berlese thus sums up his re- 
searches on the mode of impregnation and the development of the asco- 
spores in Tuber brumale. The ascus, when scarcely differentiated from 
the supporting filament, contains two nuclei which fuse together at an 
early period, so that in the fully formed ascus there is only one. This 
nucleus then multiplies by three acts of karyokinetic division. At the 
same time there appears in the ascus a quantity of cytoplasm which 
serves for the development of the ascospores. As mitosis of the nucleus 
takes place within the cytoplasm, the kinoplasm becomes differentiated 
from the trophoplasm in the form of filaments radiating from two points 
which constitute the poles of the spindle. The kinoplasm determines 
the formation of the parietal layer of protoplasm of the ascospores, which 
becomes differentiated within the trophoplasm. The nucleus of the 
ascospore divides, giving rise to four or six daughter-nuclei. 
Adaptation of Uredinese to different Host-Plants. ||— Herr P. Dietel 
discusses the question whether certain Uredinese which are now confined 
* Nouv. Mem. Soc. Imp. Nat. Moscou, xv. (1898) pp. 275-386 (1 pi.). 
t Comptes Rendus, cxxix. (1899) pp. 123-5. X Cf. this Journal, ante, p. 520. 
§ Riv. Patol. Veg., vii. (1899) pp. 143-52 (1 pi.). 
J| Bot. Centralbl., lxxix. (1899) pp. 81-90, 113-7. 
