662 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
ranea only, and Acctabnloides, made up of the remaining 13 species, 
five of them new. Halicoryne comprises two species. The new genus 
Chalmasia is thus defined : — Fertile cap terminal, composed of free 
wedge-shaped rays, united only by the calcification ; corona inferior 
wanting; segments of the corona superior not touching each other 
laterally, knob-shaped, and not sharply delimited towards the base; 
spores free, with thick much calcified membrane, and coarse cuticu- 
larised outer layer. It includes only one species, from the West Indies. 
In Acicularia are comprised one recent and three fossil species. 
The author suggests that the cap of Acetabularia corresponds to a 
true zoosporange, the zoospores of which no longer develope cilia and 
do not escape, but rather surround themselves with a membrane at the 
place of origin, and enter at once into a resting stage. After a 
lengthened rest these spores then give rise to the sexual generation of 
gametes. In the development of the cap, the whole margin first makes 
its appearance in the form of a continuous cushion below the arched 
apex of the shoot. The spores of Chalmasia are characterised by a 
remarkably thick membrane, which is beautifully stratified and sur- 
rounded by a definite coarse cuticular layer. As in the other genera 
the spores possess a removable lid. 
Structure of Voivox.*— Prof. A. Meyer calls attention to a distinc- 
tion between the structure of the globes of Volvox globator and those of 
V. aureus. The membrane of the comparatively large globe of V. globator 
consists of only a single thin layer, the outer strata of which are gela- 
tinous, the central stratum alone relatively solid. In V. aureus the 
membrane is comparatively thick and the cavity comparatively small. 
The membrane is here homogeneous, and is perforated only by the open- 
ings through which the cilia project. In both species the globe is divided 
into two hemispheres, one of which is trophic, and consists of cells 
united to one another only by simple protoplasmic threads, which 
do not become either sexual cells or parthenospores ; the other is the 
generative hemisphere, in which lie the reproductive cells, united to one 
another by numerous protoplasmic threads. In both species, when in 
motion, the trophic hemisphere is in front, a position favourable for the 
nutrition of the organism. 
Fungi. 
Influence oHCoId on Spore-Germination.f — Prof. J. Erikson has 
made some laboratory experiments with spores of fungi, to see if the 
action of cold had an accelerating influence on germination. From the 
table given it would appear that cold of itself does not appear to possess 
the power of quickening the spores ; indeed, germination seems occa- 
sionally to be quite unaffected by low temperatures. It would, however, 
appear that germination may be promoted, at any rate under natural 
conditions, when spores are exposed to a period of moisture followed by a 
spell of cold. 
Value ^offeMineralkSaltSefor Fungi. :f — Herr C. Wehmer deprecates 
the attempts of pother observers to draw too general conclusions on this 
* Bot. Centralbl., lxiii. (1895) pp. 225-33 (4 figs.). Cf. this Journal, 1891, p. 226. 
t Centralbl. f. Bakteriol. u. Parasitenk., 2 le Abt., i. (1895) pp. 557-65 (1 fig.). 
t Ber. Deutsch. Bot. Gesell., xiii. (1895) pp. 257-65, Cf. this Journal, ante r 
p. 545. 
