604 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
cases of Phragmidium Pubi-Ideei, Uropyxis Steudneri, Diorchidium, 
Pavenelia, and Gymnosporangium. 
Fungus Flux of Trees.* — Prof. F. Ludwig has examined the ruby- 
red transparent gummy substance exuded from the bark of the horn- 
beam, and finds that it consists almost entirely of curved, highly- 
refracting bodies which, from the lively movements they display when 
a solution of the gummy mass is made, and from the facility with which 
they pick up anilin dyes, are easily mistaken for bacteria. They are, 
however, the microconids (spermatia, Pycnospora ) of a Hyphomycete, 
which is the direct cause of the gummy flux, and owing to the presence 
of which the tree becomes diseased. 
A very similar condition is found to exist in the sweet chestnut ; for 
this tree suffers from a disease which appears to be associated with 
microconids similar to those found in the hornbeam. In the chestnut the 
wood undergoes a peculiar maceration, which makes it look as if it had 
been worm-eaten, and this is apparently due to the penetration of the 
tissue and vessels by a mycele which, after transformation into a gummy 
fluid, and the evacuation of the latter leaves the tree in this condition. 
Thus the course of events appears to be the formation of pycnids which 
send mycelial extensions into the tissues, and from this the gummy fluid 
and microconids are produced. 
Actinomyces.j — Sig. G. Gasparini takes account of no less than 
eighteen species of this genus, and describes those which have been 
adequately determined. Apart from the systematic part of the paper, 
the author states his general conclusions as to the life-history, varia- 
tions, and pathological effects of these important parasites. Only a few 
samples can be quoted. The normal reproduction is by means of free 
aerial spores (conids) ; and when, through deficiency of oxygen or some 
other cause, the production of aerial filaments is prevented, toruloid 
aggregations in the mycele acquire the value of spores. The bovine 
actinomycosis may be produced by diverse varieties. Isolated forms 
become in culture more greedy of oxygen, and may lose their power of 
developing anaerobically and their virulence. Their occurrence is quite 
independent of the diet of their host. From the air, the water, the 
soil, Ac., the spores find their way to some solution of continuity on the 
skin or mucous membrane of the animal. 
Fungi of Favus. — Herr Biro J describes culture-experiments with 
the favus-fungus on bouillon, potato, meat-pepton-gelatin, and meat- 
pepton-agar ; also microscopical examination of Elsenberg’s two varieties. 
The fungus consists of a mycele composed of filaments with outrunners ; 
the hyphae produce spores, and often branch dichotomously. The best 
staining-reagents he found to be eosin and haematoxylin. The three 
species, Achorion eutytlirix , A. atacton , and Biro’s fungus, gave identical 
results. The parasite enters the hair-sac, finds its way between this 
and the surrounding peripheral portion, raises up the epiderm, and is 
seen through the raised epidermal layer as a yellow dot. There appears 
to be no ground for the conclusion that there are several favus-fungi. 
* Ceniralbl. f. Bakteriol. u. Parasitenk., xvi. (1894) pp. 58-61. Cf. this Journal, 
1892, p. 83. f Atti Soc. Tosc. Sci. Nat., ix. (1894) pp, 64-89. 
I Arch. f. Dermat. u. Syphilis, 1893, Heft 4. See Centralbl. f. Bakteriol. u. 
Parasitenk., xv. (1894) p. 69. 
