624 SUMMARY OF CURRENT RESEARCHES RELATING TO 



of Miimr were of Tan' occurrence in comparison with other filamentous 

 fungi : Penicilliwn, Aspergillus, and Cladosporium being the commonest. 

 The author also tested different soils for species that might be growing 

 there, and he found that M . hiemalis was the most abundant: other 

 species grew in special localities, as, for instance, M. Ramannianus, 

 which occurred in pine woods. A number of new species were dis- 

 covered and described in the course of the work. 



Sexuality in the Ascomycetes.* — A. Guilliermond continues his 

 review of the work recently done on this subject. He takes up first the 

 yeasts, touching on the question of the nucleus, the existence of which 

 he considers well established. He describes conjugation as it is found 

 in Zygosaccharomyces and others, and these conjugations he considers 

 settle the question of the origin of the yeasts, which are autonomous, 

 and not derived from other forms. Exoascus is next considered : nuclear 

 fusion has been demonstrated in the ascogenous cells while still under 

 the cuticle of the host. 



The most important work has been done on the higher Ascomycetes 

 on Laboulbmia by Thaxter, and on' Pyronema by Harper. Sexual 

 conjugation has been observed by them and subsequent workers. 

 (Inilliermond follows each research, and records the points in which the 

 results vary or agree. The original figures in many cases are repro- 

 duced, and add to the interest and value of the papers. 



Taphrina Alni-incanse.f — This fungus infests the catkins of Alnus 

 incana, and C. von Tubeuf finds that it also attacks the young shoots. 

 He found the deformations on the young branches ; the asci were 

 entirely similar to those of the fungus on the catkins, and were without 

 a stalk-cell ; the leaves also showed the red coloration which they never 

 do when attacked by T. epiphylla. The author further notes that the 

 swellings on the leaves of poplars due to T. aurea are occasionally 

 developed on the under surface of the leaves. 



Haustoria of Meliola and Asterina.J — Rene Maire has attacked 

 the vexed question as to the parasitism of these fungus-genera. The 

 allied Capnodkim grows on the excreta of aphides, but no trace of 

 animal substratum was to be found in their case. Careful preparation 

 of microscopic sections showed distinct haustoria penetrating the host- 

 plant, and so providing nourishment for the parasite. These sucking- 

 organs are very constant and very simple in Meliola, but in Asterina 

 they vary from one species to another in their form and in the degree of 

 penetration into the host-plant, in some species only the epidermal cells 

 being reached, in others the hypodermal layer. 



Notes on Ascomycetous Fungi. — F. Theissen§ discusses Spegazzini's 

 monotypic genus Diatrypeopsis, which he has found frequently in Brazil. 

 From his observations he concludes that the fungus is identical with 



* Rev. Gen. Bot., xx. (1908) pp. 85-9, 111-20, 178-82, 298-305. 

 t Nat. Zeit. Land.-Forstw., vi. (1908) pp. 6S-73. See also Bot. Centralbl., cvii. 

 (1908) pp. 520-1. 



X Ann. Mycol., vi. (1908) pp. 124-8 (4 figs.). § Tom. cit., pp. 91-4. 



