Dec. 1903] The Finding of Puccinia Phragmitis , Etc. 219 
1. The mycelium, pycnidia, etc., are preserved in their nat¬ 
ural form and position on the surface of the host, and not all 
broken and disarranged as is the case when they are scraped from 
the surface. 
2. In many cases of the forms the mycelium is SO' scanty 
that in an ordinary mount or section too little is present to show 
its nature, while by this method a large area is presented so that 
all the mycelium is sure to be present. 
3. Pycnidia in all stages of development may be easily ob¬ 
tained and studied in their normal position and relation to the 
mycelium on which they are borne. 
4. In order that the spores may be shown, a pycnidium at 
the side of the mount may be crushed with a dry scalpel while 
the material is still in the clearer. 
5. By removing the color of the host cells there is nothing 
to interfere with the examination of the mycelium by transmitted 
light. 
This method will be found most valuable in the case of those 
fungi having dark colored mycelium. Hyaline mycelium would 
be scarcely more evident than the colorless host cells. The whole 
secret of the process lies in the fact that the pigment in most of 
the higher plants (the hosts) is bleached by Potassium hydrate, 
while that of the parasite is not affected. 
Very excellent results have been obtained in the case of the 
following fungi: Cladosporium carpophilum on the bark of 
peach twigs, Leptothyrium pomi on the fruit of cultivated apples, 
Vermicularia circinans on the outer leaves of onion bulbs, Sphaer- 
opsis malorum on leaves of cultivated apples, Macrosporium cu- 
cumerinum on leaves of Cucumis melo. 
Botanical Department, Cornell University. 
THE FINDING OF PUCCINIA PHRAGMITIS (SCHUM.) 
KORN. IN NEBRASKA. 
BY JOHN M. BATES. 
On June 14th, 1901, while collecting asparagus rust in a 
garden in Kearney, Nebr., I found six or seven spots of pure 
white aecidia on Rheum raphonticum on the under side of the 
leaves. It was at once pronounced to be Puccinia phragmitis, 
and appeared to be on a new host for this country. This sug¬ 
gested further study of the species. This garden is three miles 
from the Platte River, and probably there is no patch of Phrag- 
mites phragmites nearer than this. About a mile west of Calla¬ 
way, Custer County, there are several patches of this grass, and 
on this I found rust on the 28th of August of last year. The 
Uredo stage was just passing away at that date. This brought 
