ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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gospores themselves are seen to be chlamydospores from their gemma- 
and oidium-like mode of formation. The order possesses three kinds of 
fructification — ustilagospores, the higher conidial form of the Idemi- 
basidii, and the lower conidial form. The ustilagospores, which are 
produced chiefly or exclusively on the host-plant, are chlamydospores 
formed in the mycele. The products of the germination of the chlamy- 
dospores (formerly described as promyceles and sporids) are, in the 
Tilletiaceae, clusters of conids, while the Ustilaginese produce lateral 
conids. The third form of spore consists of the conids formed free on 
the mycele without hemibasids. In Ustilago the hemibasids formed 
from the chlamydospores are usually 4-celled, less often 1-, 2-, or 
3-celled. 
According to the development of the fructification, Ustilago may be 
divided into three genera or sub-genera — viz. (1) Proustilago ( U. longis- 
sima , grandis), with repeated formation of fructification, though variable 
in form ; (2) Hemiustilago ( U. Vaillantii, bromivora ), with repeated but 
constant formation of hemibasids ; (3) Euustilago, with only one forma- 
tion of hemibasids. In this last subgenus there are forms in which, in 
addition to the hemibasids, there is abundant formation of conids, others 
in which they are not strongly developed. 
The fusion of conids, or of the separate cells of the hemibasids, 
regarded at one time as a process of conjugation, is shown by the author 
to be an entirely secondary process which has nothing to do with 
sexuality. It consists simply of a union of masses of protoplasm, 
which takes place only when the nutriment is defective. Both cells are 
capable of independent germination. 
Rust of Oryza and Setaria.* — Dr. O. Brefeld announces the inter- 
esting discovery that the parasitic rusts on Oryza sativa and Setaria 
Grus-Ardese , hitherto known as Ustilaginoidea Oryzae and U. Setarise , are 
in reality stages of development of ascomycetous fungi allied to ergot. 
This was proved by cultivation of the so-called uredospores in nutrient 
solutions, where they give rise to an abundantly septated mycele bearing 
minute conids similar to those of Pilacre. The rust of Setaria produces 
true sclerotes. From these sclerotes were obtained peritheces contain- 
ing true asci, each ascus with eight ascospores. Ustilaginoidea must be 
removed from the Hemibasidii, and must be regarded as a genus of 
Hypocreacese allied to Tilletia ; the ustilagospores are simply a secon- 
dary form of reproductive organs. The small colourless conids which 
are first of all produced on the mycele are of transient duration, and are 
succeeded, when the mycele has attained its full development, by black 
spores, which the author regards as a kind of chlamydospore. 
Setehellia.f — A further examination of this genus of Ustilaginem 
leads Herr P. Magnus to the conclusion that the germinating sorus is 
closely analogous to the hymenium of a simple Hymenomycetous 
fungus, the unbranched and unseptate promyceles corresponding to the 
unseptated basids, from the apex of which spring the sterigmas and 
spores. 
* Bot. Centralbt., lxv. (1896) pp. 97-108. 
f Bor. Deutsch. Bot. Gesell., xiii. (1895) pp. 468-72. 
