442 .SUMMARY OF CURRENT RESEARCHES RELATING TO 



Sterig-matocystis versicolor. — Henri Coupin and Jean Friedel,* 

 have studied the biology of this fungus, which changes its form and 

 colour according to the -medium in which it is grown. It resembles 

 closely St. nigra, except that it will scarcely grow in the presence of 

 an acid, while St. nigra develops well in an acid solution. Normally, 

 it is of a rusty red colour, and secretes a pigment varying from clear 

 yellow, when an acid is present, to deep red when an excess of car- 

 bonate of potassium renders the solution alkaline. 



Paul Yuillemin f also publishes notes on the same subject. He 

 distinguishes the two colour forms, green and rose, due to the medium 

 in which the fungus is cultivated, and therefore depending on definite 

 chemical properties. The colour of the spores is less easily controlled, 

 as both kinds may appear in the same growth. Cultures were made 

 on the same substratum of green and rose-coloured conidia, and it was 

 found that the colour form was constant. In this case the medium was 

 not the determining cause of the colour. 



Culture of Oospora destructor.^ — This fungus, previously known 

 as Isaria destructor, is parasitic on insects. A. Vast cultivated the spores 

 on a large variety of media, and describes the influence that the sub- 

 stratum had on the growth of hyphse and conidia. The fungus de- 

 veloped more quickly and luxuriantly on potato than on any of the 

 other substances experimented with. In some of the cultures, patches 

 of sterile yellow mycelium were developed, in others there was a con- 

 siderable formation of crystals. Vast infected the larvas of Coleoptera 

 by plunging them in sterilised water containing conidia, or in brushing 

 them over with the conidia themselves. 



Conidial Form of Daldinia concentrica.§ — Marin Molliard has 

 gone over the work done by Tulasne on this fungus. He got the same 

 conidial growth, but some additional discoveries have enabled him to 

 place the conidial fungus in the genus Nodulisporum, considered by some 

 authors to be a section of Botrgtis. Molliard finds that it is in many 

 points similar to a Mucedine studied by Matruchot, Gostantinella 

 cristata, and he thinks that probably the latter is the conidial form of 

 a Pyrenomycete closely related to Xylaria. 



Fungi imperfecti.|]— G. Lindau is the author of the section Hypho- 

 mycetes in the " Kryptogamen-Flora," the first part of which has just 

 been issued. He discusses their systematic position in the preface, and 

 states the difficulty of classifying them properly. Many of them have 

 been proved to be conidial forms of Ascomycetes, but while it has been 

 proved that allied species of Ascomycetes often have very similar conidial 

 forms, it as often occurs that neighbouring Hyphomycetes may form part 

 of the life-cycle of widely separated higher fungi. 



The author remarks, too, on the difficulty in recognising the plants 

 which the older writers had under observation. The type specimens have 



* Comptes Rendus, cxxxviii. (1904) pp. 1118-20. f Tom. cifc., pp. 1350-1. 



t Bull. Soc. Mycol. France, xx. (1904) pp. 66-71. 

 § Torn, cit., pp. 55-60 (1 pi.) 



|| Rabenhorst's Kryptogamen-Flora. Band. I., Abtb. viii., Lief. 92. 135 pp. 

 Leipzig, Eduard Rummer, 1904. 



