94 SUMMARY OF CURRENT RESEARCHES RELATING TO 



identical, but one, the ascogonium, gradually becomes richer in contents. 

 Both branches are multinucleate, seven or eight nuclei in the ascogonium, 

 three or four in the antheridium. A cell is cut off at the tip of the 

 ascogonium analogous to the trichogyne of Monascus ; after the separa- 

 tion of the trichogyne only four or five nuclei are to be seen in the 

 ascogonium, but they are larger, and they furnish, after division, the 

 copulatory nuclei of the asci. Dangeard explains the theory of this 

 retarded copulation by comparison with the Siphomycetes. He considers 

 it to be sexual fertilisation. 



Cytology of Galactinia succosa.*— It. Maire, with a view to elucidate 

 the affinity between nuclear evolution in the Ascomycetes and the 

 Basidiomycetes, has studied one of the higher Pezizas, Galactinia succosa. 

 This species is of interest in having laticiferous elements which are still 

 but little known in the Ascomycetes. The author finds that it shows a 

 real relationship with the Basidiomycetes from the point of view of its 

 nuclear evolution ; the presence of a group of synkaryons before the 

 formation of the ascus, places it above the other Ascomycetes : we find here 

 the first suggestion of that phase in the life-history, the synharyophyte, 

 which plays so important a part in the development in the Basidiomycetes. 



Infection Experiments with Nectria ditissima.f— Bud. Aderhold 

 refuses to accept Brzezinski's theories as to the origin of canker in fruit 

 trees. The latter had failed to induce canker by infection with Nectria 

 spores, but in all cases had done so by injecting Bacterium Mali into the 

 trees. By repeated experiments Aderhold has proved that Nectria causes 

 the wounds known as canker, not only in apple and pear trees, where it 

 is well known, but in cherry trees and plum trees, where its parasitism 

 was unsuspected. The writer has found canker wounds on cherry trees 

 not due to artificial infection, in all points resembling those induced 

 by the introduction of Nectria, but he was unable to find the fruiting 

 form of the fungus. He calls for further proof by Brzenzinski of his 

 theory before it can be received. 



Morphological and iBiological Researches on Stysanus.J — F. 

 Gueguen has come to the conclusion that Stysanus Mandlii is only a 

 form of St. Stemonites. From both he developed a similar perithecial 

 form, Melanospora siysanophora. The ascus spores were cultivated in 

 turn, and produced a form of Acladium, brown chlamydo-spores and 

 new perithecia, but Gueguen failed to reproduce the Stysanus form. He 

 cultivated also Echinobotryum atrum, so frequently found on Stysanus^ 

 He considers it a sessile form of St. ftmetarius. He has classified some 

 other forms with St. Stemonites, and thinks that, though usually sapro- 

 phytic, it may grow as a true parasite. 



Rhizoctonia violacea.§ — Jakob Eriksson completes his account of 

 experiments with this fungus-disease of roots. He had already recorded 

 that the parasite can transfer itself to other roots, and that in succeeding 



* Coniptcs Bendus, cxxxvii. (1903) pp. 769-71. 



f Cenlraibl. Bakt., x. (1903) pp. 763-6. 



% Bull. Soc Mvcol. France, sir. (1903) pp. 217-44 (3 pis.). 



§ Centralbl. Bakt., x (1903) pp. 766-75 (1 pi. and 1 tig.). 



