228 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
tJiocepJiala, polyspermia , aversa , and dichotoma ; (2) Corniculatse, (a) Ses- 
siles, V. repens , sessilis, clavata, and pachy derma ; (6) Racemosae, V. 
hamata, terrestris , uncinata , and racemosa ; (3) Anomaly, F. geminata and 
. de Bar y ana. 
Protoplasmic Communications in Volvox.* * * § — Prof. A. Meyer lias 
studied the nature and purpose of the protoplasmic connections between 
the cells in Volvox globator, V. aureus , and V. tertius sp. n., the last 
species characterised by a stratification of the gelatinous membrane, 
and displaying also different heliotropic properties. Both the optical 
and the microchemical phenomena indicate that the protoplasmic fila- 
ments which connect cell with cell are threads of normal cytoplasm 
displaying no special structure. These threads occur in very much 
greater numbers in the generative than in the trophic hemisphere. 
Comparing the protoplasmic communications in Volvox with those 
which have been detected in other families of the vegetable kingdom, the 
author regards them of the same nature as those of Angiosperms, as well 
as those which occur in the animal kingdom, and probably also of the 
Rhodophyceae, Phaeosporeae, and Schizophyceae. It is probable that such 
connections exist between all the cells of an individual, and that every 
individual, both vegetable and animal, is a unit-mass of cytoplasm. 
Fungi. 
Influence of Light and of the Substratum on the Development of 
Fungi. t — M. A. Lendner has experimented on the effect of the access 
•and withdrawal of light on various Fungi, chiefly Mucorini and Ascomy- 
ectes, grown on different media. The results differ with different species. 
All the Mucorini developed sporanges under the influence of light when 
grown on solid substrata ; in liquid media the results varied with the 
species. In the case of the conidial forms of the Ascomycetes, conids 
were always formed under the influence of alternate day and night ; 
under continuous light, the results varied with the species. The author 
•regards all the phenomena of heliotropic sensitiveness in Fungi as con- 
nected simply with nutrition. 
Parasymbiosis of Fungi.f — Prof. W. Zopf finds fresh confirmation 
►of his theory that many of the fungi which grow on lichens are not true 
parasites, but have a kind of symbiotic relationship to the host, which he 
terms parasymbiosis , the hypbae of the “ parasite ” enveloping the algal 
constituent of the liclieD, without inflicting any injury upon it. The 
observations were made on Bhymbocarpus punctiformis, which attacks 
Bliizocarpon geographicum, and on Conida punctella and C. rubescens , 
growing on Diplotomma alboatrum. The hyphae of the parasite were 
distinguished from those of the lichen by the fact that the latter are 
►coloured a beautiful blue by iodine solution, while the former arc not. 
Effect of Low Temperatures on Mucor Mucedo.§— Prof. R. 
Fhodat finds that this fungus is not killed by subjection to very low 
* Bot. Ztg., liv. (1896) ] te Abt., pp. 187-217 (1 pi. and 7 figs.). Gf. this Journal, 
1895, p. 662. f Ann. Sci. Nat. (Bot.), iii. (1897) pp. 1-61 (7 figs.). 
t Ber. Deutsch. Bot. Gesell., xv. (1897) pp. 90-2. Cf. this Journal, ante, p. 151. 
§ Bull. Herb. Boissier, 1896, pp. 8D0-7. 
