213 



MICROSCOPIC FUNGI. 



A SHORT course of demonstrations on Microscopic Fungi, by Mr. M. C. Cooke, 

 are just concluded. They were delivered on alternate Tuesday evenings to a 

 class of about twenty members of the CJub. The first lecture commenced with 

 a brief History of the Study of Microscopic Fungi in Britain, and the publica- 

 tions on the subject ; this was followed by a description of what constitutes a 

 fungus and the principal features which distinguisli these from the other inferior 

 cryptogams. The system of classification adopted for these organisms, was 

 next discussed, and the structure of the larger fungi explained. The two orders 

 which were illustrated in this lecture were the Hymenomycetes, of which the 

 common mushroom was taken as the type, and the Gasteromycetes, of which the 

 common Puff Ball was the type. The microscopic characters were those to 

 which attention was principally directed, and it was shown that the latter order 

 contained a large number of very interesting minute species, especially the 

 spiral threads of Trichia, the reticulated skeletons of Stemonitis, the banded 

 or warted threads of Arcyria, and the goblet-shaped perithecia of Craterium. 



The second lecture was devoted almost wholly to that section of the dust-like 

 fungi {Coniomrjcetes) which are found as parasites upon living plants, such as the 

 Cluster cups (jEddium) , Rusts (Trichobasis) , Brands and mildew of the genera 

 Pregma, Puccinia, and Triphragmimn, the Bunt {Tilletia), and Smuts ( CsiiZago) . 

 We have already published the remarks on Bunt spores, which were communi- 

 cated about the same time, at one of the ordinary meetings of the Club. The 

 dimorphism and trimorphism which prevails in this group was fully and clearly 

 explained. The best modes of collecting, preserving, and mounting the various 

 species were commented upon, and the lecture concluded with an enumeration 

 of the principal characters employed in the classification of the gioup, and the 

 features whereby the members of one genus are to be distinguished from those 

 of another. 



The third demonstration was confined to that section of the Hypliomycetes , 

 which are usually called the "White Moulds," or Mucedines, The structure of the 

 Potato mould, and its modes of increase were detailed at length, to serve as a 

 type of the important genus Peronospora, so injurious to many kinds of culti- 

 vated plants. Numerous examples were adduced of the beauty of form in many 

 of the little plants of this group, which were admirably illustrated by a large 

 series of well-executed diagrams. In fact all the lectures were profusely illus- 

 trated by at least one hundred diagrams altogether, which were prepared 

 specially to illustrate this course. This lecture concluded with the blue moulds 

 found upon paste, cheese, and other substances, and a comparison of the 

 structure of the Mucedines with the Mucors belonging to another order, and 

 which in some cases at least, are a higher development of the Mucedines. 



The fourth lecture was occupied principally with the remainder of the 

 Bypliomycetes, and chiefly those that are termed " Black Moulds," which occur 

 in velvety patches on the dead stems of herbaceous plants, on twigs, and on 

 rotten wood. The rather extensive genus H eJ minthosporiuin was recommended 

 as offering a variety of forms in this group, and as having many common 

 species. The form of the fruit in a number of these moulds was compared with 

 the fruit of some of the Ooniomycetes and Sphoeriacei. 



