446 SUMMAEY OF CURRENT RESEARCHES RELATING TO 



motion. When it comes into contact with the gelatinous sheath of an 

 alga, it bores through the jelly by means of the flagellum, and becomes 

 the stalk of the sporange. The systematic position of the genus is 

 doubtful. 



Cytology of the Hymenomycetes.* — Pursuing his researches on 

 the cytology of the Hymenomycetes, R. Maire states that in Hygrocybe 

 ■conica we have the only example at present known of the development 

 of basic! s without any fusion of nuclei. The cells of the lamellas are 

 plurinucleate ; while those of the sub-hyruenium contain only a single 

 nucleus with two chromosomes, dividing by mitoses resembling those 

 of the basids. 



M. Maire explains the diversity in the results obtained by different 

 observers as to the number of chromosomes, by the statement that, after 

 the appearance of the centrosomes and of the spindle, and the partial 

 or entire disappearance of the nuclear membrane, the chromatic fila- 

 ments are in the first place transformed, not into chromosomes, but into 

 a variable number of strongly chromatophile granulations, the proto- 

 chromosomcs, which reunite, at the end of the prophase, into two definite 

 chromosomes, placed side by side in the middle of the spindle, and 

 which then usually divide longitudinally. 



Merulius lacrymans.f — G. Marpmann gives a detailed account of 

 the appearance presented by this destructive fungus, and of the injury 

 inflicted by it on wood. The microehemical reactions by which its 

 presence can be recognised are given, especially those with Nessler's 

 reagent. 



"Bleeding" of Stereum sanguinolentum. J — According to V. 

 Kindermann, the seat of the blood-red pigment of the juice which 

 exudes from this fungus when wounded is special hyphaa which he terms 

 tannin-hyphae, occurring mostly in the sub-hymenial layer ; in the 

 hymenium they run parallel with the basids. They are somewhat wider 

 than the other hyphae of the receptacle, their diameter being from 29 to 

 52 fx. Here and there is an irregular transverse septation. Towards 

 the somewhat club-shaped projecting apices the membrane is much 

 thinner. The fresh tannin-hyphas contain a reddish-brown homo- 

 geneous fluid, with numerous oil-drops, which becomes blood-red on 

 exposure by oxidation. Its function appears to be to hinder decay. 



Spore-formation of Acrospeira. § — Experiments made by R. H. 

 Biffen with various culture-media support the view that an altera- 

 tion in the food-supply and other external conditions may induce a 

 change in the external characters of the spores rather than in their 

 nature. In Acrospeira mirabilis, in addition to the ordinary chlamydo- 

 spores, groups of chlamydospores were produced on chestnut-agar 

 surrounded by a thick envelope of several layers of cells. The sub- 

 merged hyphae also produced flask-shaped structures from which endo- 

 conids arose. 



* Comptes Rendus, cxxxii. (1901) pp. 861-3. Cf. this Journal, 1900, p. 620. 



t Zeitschr. f. angew. Mikros., vii. (1901) pp. 1-12. 



X Oesterr. Bot. Zeitschr., li. (1901) pp. 32-5 (1 fig.). 



§ Proc. Cambridge Phil. Soc, xi. (1901) pp. 136-8. 



