ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
777 
Algae. 
Influence of the Concentration of Sea-water on the Growth of 
Algae.* * * § — Dr. F. Oltmanns finds, from a series of experiments on various 
sea- weeds, especially species of Fucus , that an alteration in the proportion 
of salts contained in the water, say between 1*0 and 1*8 per cent., is 
prejudicial to their growth only when the alteration takes place suddenly ; 
if it is effected slowly, the injurious influence is but slight. The cause of 
the injury is probably the inability of the cells of the plant to adapt 
themselves suddenly to changes of turgor. Since different species show 
different degrees of inability in this respect, alterations in the 
constitution of the sea -water caused by variations in the influx of fresh 
water have a material influence on the marine flora. 
Endophytic Algae.t — Herr M. Mobius gives a conspectus of all the 
endophytic algae known, of which he enumerates ninety-two species, 
including the new Bolbocoleon ? endophytum , which inhabits the cell- 
walls of Cladopliora fracta. Of these some have been observed only on 
one host, others on several. They inhabit other Algae — Ehodophyceae, 
Phaeophyceae, and Chlorophyceae ; very rarely Fungi ; Musci — especially 
Sphagnum , more often Hepaticae ; Azolla among Vascular Cryptogams ; 
several orders of Gymnosperms, Monocotyledones, and Dicotyledones ; 
among animals, sloths and a great variety of marine species. With the 
exception of those which inhabit the shells of molluscs or of turtles, they 
penetrate either the cells or only the cell-walls of both plants and 
animals. They may or may not be injurious to the host. 
“ Meteor-paper.” f — M. J. Istvanffi gives the following as the composi- 
tion of several specimens of this structure gathered by him in Germany 
and Hungary : — (1) Cladophora fracta var., with specimens of Oscillaria 
tenuis , Chlamydomonas Pulvisculus , Herposteiron repens , (Edogonium 
longatum , and Hantzschia Amphioxys ; (2) Lyngbya turfosa , with nine 
species of unicellular algae ; (3) (Edogonium tenellum ; (4) a loose weft 
of the resting-form of a species of Conferva ; (5) Microspora 
fioccosa, together with specimens of Oscillaria tenuis , Ulothrix subtilis , 
twenty-one species of diatoms, three of desmids, and one of Pleuro- 
coccaceae. 
Reproductive Organs of Floridese.§ — Mr. T. H. Buffham describes 
the antherids in the following species of Florideae, in which they had not 
previously been observed or figured : — Bangia fusco -purpurea , Callitham - 
nion arbuscula , Griffithsia barbata, Ptilota elegans , Ceramium echionotum , 
C. transcurrens , C. flabelligerum, Phyllophora membrani folia , Plocamium 
coccineum , Nitophyllum laceratum, Lomentaria Jcaliformis, Chondriopsis 
dasyphylla , Bytiphlcea pinastroides, Polysiphonia elongata. Procarps and 
trichogynes were also observed in Callithamnion tetragonum , C. roseum, 
C. byssoideum , C. granulatum , Griffithsia barbata, and G. corallina ] in 
most cases the pollinoids were detected adhering to the trichogynes. In 
Griffithsia corallina and Ceramium flabelligerum there are two trichogynes 
to each procarp. Callithamnion byssoideum was found bearing branching 
* SB. K. Breuss. Akad. Wiss., 1891, pp. 193-203 (1 pi.), 
f Notarisia, vi. (1891) pp. 1221-36, 1279-86, 1291-1304 (1 fig.), 
t Temieszetrajzi Fiizetek, vol. xiii. See Bot. Centralbl., xlvii. (1891) p. 51. 
§ Journ. Quek. Micr. Club, iv. (1891) pp. 246-53 (2 pis.). 
1891. 
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