312 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Herr P. Magnus.* It is well distinguished specifically from S. Cas - 
tagnei. 
Fungus-Galls on Ferns.f — In addition to the case already observed 
of galls formed on Aspidium spinulosum by Taplirina jilicina, Dr. K. 
Giesenhagen now records the formation of galls on Aspidium pallidum by 
Taplirina fusca sp. n., and on the same fern by T. cornu-cervi. 
Sexuality of the €ollemacese.+ — Herr E. Baur gives some details 
respecting the sexual process in the Collemaceae ( Collema crispum ). The 
thallus is of two dypes : — the first is luxuriant and strongly developed, 
with no or very few apotheces ; the second much smaller, and densely 
covered with apotheces. The former type bears abundance of carpo- 
gones ; while on the latter they are companftively rare. Whenever tbe 
whole of the trichogyne could be observed, a spermatium (pollinode) 
was always found attached to its tip, and orifices were observed in the 
wall of the trichogyne, through which the nucleus of the pollinode may 
have passed. A large number of ascogone-cells take part in the forma- 
tion of the asci ; and the author believes the actual process of impregna- 
tion to be comparable to that in some Florideae and in the Laboulbeniaceae. 
The first ascogone-cell must be regarded as the egg-cell (oosphere) ; the 
sperm-nucleus fusing with its nucleus. The posterior ascogone-cells 
are auxiliary cells. The impregnated ovum-nucleus divides, and a 
daughter-nucleus passes into each auxiliary cell. 
Coalescence of the Margins of the Thallus in Crustaceous Li- 
chens.§ — Herr G. Bitter describes this phenomenon in a large number of 
species, and classifies the modifications of the process under the follow- 
ing heads: — Coalescence of the margins of individuals of the same 
species ; this may take place with or without the formation of a separa- 
ting seam ( Abgrenzungssaum ) ; Formation of separating seams in the 
coalescence of individuals of different species ; Crustaceous Lichens 
which overgrow neighbours of a different species (foliaceous and arbor- 
escent lichens) may also be overgrown by Pertusariacege ; Saprophytic 
consumption of the remains of lichens by other lichens ; Pushing aside of 
lichens by their hypopliloeodic neighbours ; Parasitic Fungi which have 
been erroneously described as Lichens ( Karschia scabrosa , Lecidia intu- 
mescens) ; Epithallinic outgrowths of Crustaceous Lichens. Behaviour 
of Foliose Lichens in contact with Lichens of a similar thallus-form. 
Nucleus of the Yeast-Plant. — From an exhaustive investigation 
of this subject, Mr. H. Wager || states that all yeast-cells ( Saccharomyces 
Cerevisise, Ludivigii, and pastorianus) contain a “ nuclear apparatus.” In 
the earlier stages of fermentation this consists of a nucleole, in close 
contact with a vacuole which contains a granular chromatin network, 
and is probably the result of the fusion of smaller vacuoles. In the 
later stages of fermentation this vacuole may disappear. The nucleole 
is present in all cells, and is apparently a perfectly homogeneous body. 
In the process of budding, the division of the nuclear apparatus 
does not exhibit any definite stages of karyokinesis, but must be regarded 
* Tom. cit., pp. 331-4 (1 pi.). t Flora, lxxxvi. (1899) pp. 100-9 (6 figs.). 
X Ber. Deutsch. Bot. Ges., xvi. (1898) pp. 363-7 (1 pi.). 
Jahrb. f. wiss. Bot. (Priny;sheim), xxxiii. (1898) pp. 47-127 (14 figs.). 
Ann. of Bot., xii. (1898) pp. 499-543 (2 pis.). 
