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Germination of the Spores of Cerebella Paspali. 
By Gero. F. ATKINSON. 
(PLATE 183.) 
Specimens of Cerebella Paspali C. & M. were collected by the 
the writer in August, 1891, at Auburn, Ala. on Paspalum platy- 
caule. Since there is some doubt as to the relationship of this 
genus to the other genera of the Ustilagine, it seemed well in 
the spring of 1892 to undertake the germination of the spores, 
that their behavior under those circumstances might be observed. 
Cultures were made in Van Tieghem cells in water, and the 
development of the mycelium carefully traced. The first sowing * 
was made April 2d, and in twenty-four hours the spores were 
§erminating, as shown in figures 2 and 3. One or all of the cells 
of the glomerules, or spore balls, may germinate. The germ 
tubes are rich in granular protoplasm, and are also abundantly 
‘upplied during their early growth with quite numerous highly 
tefringent granules. Septa arise also quite early, dividing the 
threads into cells, which are at first in length two or three times 
their diameter. Later they may become shorter by further divi- 
sion. These threads, which are homologous with the promyce- 
lium of the Ustilaginee in common, do not seem to function as 
Promycelia in the ordinary sense, 2. ¢., they do not bear sporidia. 
On the other hand, quite an extended weft of mycelium is devel- 
Oped and the threads branch profusely. Frequently, where 
threads or their branches from the same spore ball or from differ- 
eat apdre’ balls: come in contact fusion talked place in the same 
Manner as in the mycelium of many of the pyrenomycetous and 
hyphomycetous fungi. Figures 4 and 5 show quite an extended 
Stowth of mycelium from two spore balls, which at figure 6 is fus- 
‘Ng In several places. In a few days vacuoles appear in the proto- 
plasm of the thread cells, which become more and more prominent 
Wis the age of the thread. At the same time the older cells be- 
ae Strongly constricted at the septa, so that the individual cells, 
bh ch are now shorter by the formation of intermediate septa, are 
pearly Oval in form. Also the mycelium now begins to darken | 
