506 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
parts which are most fully illuminated. In the Crassulacese he deter- 
mined that the formation of organic acids during the night is dependent 
on the assimilation of carbon previously effected in the day-time. The 
distribution of water in the different parts of plants belonging to the 
Crassulaceae corresponds to that of malic acid ; in Opuntia and the Cras- 
sulaceae it is the most parenchymatous region that contains the largest 
quantity of water. The presence of organic acids in the tissues is dis- 
tinctly unfavourable to transpiration. 
Influence of Light on Respiration.* — Herr W. Detmer gives the 
results of a series of experiments which appear to determine that light has 
no direct influence on the respiration of plants destitute of chlorophyll ; 
while in the green parts of plants both assimilation and respiration are 
retarded by the exclusion of light for a considerable period. No daily 
periodicity could be established in the intensity of the respiration. In 
germinating potato-tubers the respiration is decidedly more intense in 
the light than in the dark, light having apparently the power of disso- 
ciating the living molecules of protoplasmic albumen. 
Formation of Sulphates and Nitrates.f — Pursuing his investigations 
on the chemical changes which take place in plants during germination, 
M. E. Belzung finds that sulphates may be formed at the moment of 
germination by oxidation of the sulphur in the albuminoid reserve- 
materials ; while nitrates are never formed by the oxidation of the nitrogen 
of the albuminoid substances, but are always transported directly into 
the seedling from the nutrient material. A process of nitrification 
unconnected with bacteria is unknown in the vegetable kingdom. 
B. CRYPTOGAMIA. 
Algae. 
Parasitic Phaeosporese.f — M. C. Sauvageau enumerates the following 
parasitic species of Phaeosporeae : — Elachista stellulata on Dicfyota dicho- 
toma, not a facultative, but a true parasite ; E. Areschougii on Himanthalia 
lorea ; E. clandestina on Fucus ceranoides ; E. scutulata in the concep- 
tacles of Himanthalia lorea ; E. pulvinata in those of Cystosira ericoides 
and discors ; Ectocarpus investiens on Gracilaria compressa and multi- 
partita ; E. velutinus on Himanthalia lorea ; E. Valiantei on Cystosira 
ericoides; E. brevis sp. n., forming yellow-brown tufts on Ascophyllum 
nodosum ; E. minimus on H. lorea ; E. luteolus sp. n., forming a light- 
yellow down on Fucus serratus and vesiculosus ; E. parasiticus sp. n., 
forming small brownish spots on Cystoclonium purpurascens , Gracilaria 
confervoides , and Ceramium ruhrum ; E. solitarius sp. n., on Dictyota 
dichotoma ; Streblonemopsis irritans on Cystosira opuntioides ; Ectocarpus 
fasciculatus on Laminaria flexicaulis. 
Reproductive Organs of Prasiola.§ — Mr. T. H. Buffham describes 
structures in Prasiola stipitata which he regards as antherids and 
“ spores ” (fertilized oosperms). The former were seen to be discharging 
* Ber. Deutsch. Bot. Gesell., xi. (1893) pp. 139-48, 149-53. 
f Journ. de Bot. (Morot), vii. (1893) pp. 87-91. Cf. this Journal, 1892, p. 825. 
% ‘ Sur quelques Algues Pheosporees parasites,’ 48 pp. and 35 tigs. ISee Bot. 
Centralbl., liv. (1893) p. 75. § Grevillea, xxi. (1893) pp. 90-2 (6 figs.). 
