MONILTA, SACHSIA AND CHALARA. 451 



This fungus closely resembles the Monilia, both in the develop- 

 ment of the vegetative organs and in respect of its fermentative 

 capacity. 



Chalara mycoderma, a name first applied by BONORDEN (I.), 

 was afterwards bestowed by L. CIENKOWSKI (III.) on a fungus 

 discovered by him in the films on organic liquids (wine, milk, 

 fruit juices, sauerkraut liquor, &c.). This species, which was 

 afterwards discovered and depicted by E. 0. HANSEN (LIX.), is 

 mentioned here in connection with the Monilia because the film 

 it produces on the surface of nutrient liquids is similar to that 

 of Monilia Candida. The extensively branched mycelium of the 

 former organism, however, consists of rafter-like aggregations 

 of elongated buds, from which globular to ellipsoidal conidia 

 separate by constriction at the points of contact of the cells. 

 These conidia, which measure about 4-6 //, are often on short 

 stalks or steriginata; and they may also be developed on the 

 individual cells into which the mycelium frequently disintegrates 

 after the manner of Oidia. Being closely packed with protoplasm 

 and therefore highly lustrous, these conidia are readily dis- 

 tinguished from the delicate, and apparently empty, elongated 

 cells, so that Chalara presents a characteristic appearance under 

 the microscope. 



315. Oidium laetis and Allied Species. 



The widely distributed Oidium lactis, the chief representative 

 of the whole clan, is classified with the Basidiomycetes by the 

 systematic mycologist, on account of the peculiar forms of vege- 

 tative reproductive cells known as Oidia, first observed in their 

 fullest development in Oidium lactis. Their form, origin, and 

 importance have already been mentioned on p. 23, vol. ii. and it 

 should also be stated that the rectangular contour of the conidia 

 is so marked that it is very difficult to mistake an Oidium cell for 

 any other kind. So long as the Oidium fruit cannot be satisfac- 

 torily assigned to the second typical, basidiomycetous fructification, 

 these Oidium species may be grouped with the fungi imperfecti, 

 since they are connected with many species of this group by 

 transition forms. We have also retained the old and characteristic 

 name, Oidium, because it is well known in all the literature of 

 fermentation, including the present work, and because, in the 

 present indefinite systematic position of the genus, it would be 

 inadvisable to employ the proposed new name, " Oospora." 



The species of the genus Oidium are characterised by a typical 

 mycelium, consisting of septated, irregularly branched hyphae, 

 which disintegrate mostly at the ends, though sometimes in the 

 middle as well into short cylindrical cells of nearly rectangular 

 contour, only the corners being rounded off a little. Budding is 

 only exceptionally observed with this genus. 



