CERTAIN SPECIES OF MUCOR 249 
Ill. TECHNIQUE 
I. COLLECTION OF MATERIAL 
Collecting was begun in the autumn of 1913, when various kinds 
of dung, including that of the horse, cow, sheep, dog, rabbit, mouse, 
and squirrel, were brought into the laboratory, placed in moist 
chambers and watched for the development of mucors. Decaying 
plant material was also employed, and the following gave positive 
results: stems of decaying apple and grape (Pyrus Malus and 
Vitis sp.), mushrooms (Collybia dryophila, Psalliota campestris), 
wood and leaves (Pinus sylvestris and Phlox sp.), Sphagnum sp., 
tomato (Lycopersicum esculentum), carrot (Daucus Carota), Brazil 
nuts (Bertholletia excelsa), puff ball (Calvatia sp.), and oak root 
with mycorhiza. In the case of the plant material used, the 
material to be tested was placed in a damp chamber until there 
was produced a growth of mold sufficient to insure a transfer to 
a poured plate. 
In the belief that the Mucor soil flora might prove interesting, 
the author undertook a series of isolations, which consisted in 
obtaining surface soil from a great variety of stations. These 
samples, except in the cases cited below, were all taken in the 
vicinity of Ann Arbor, Michigan. The following method was 
used: Petri dishes were wrapped in paper, sterilized, then taken 
to the field, where they were unwrapped and opened only long 
enough to fill them with soil. The cover was then replaced and 
sealed with a gummed label, upon which were written the collection 
data. At the laboratory the earth was saturated with sterile 
water, a drop or two of which was then transferred to a poured 
plate by means of-a flamed platinum needle. From this culture 
a pure gross culture could usually be obtained, from which, in 
turn, a single spore culture was eventually made. 
All of the forms isolated (see TABLE I), with the exception 
of Nos. 2, 4, 5, 6, 68, 69, 70, 71, and 72, were collected 
in the vicinity of Ann Arbor. The first four of these nine collec- 
tions were obtained in Chippewa County, Michigan, during the 
summer of 1914; the rest were collected in the Adirondack Moun- 
tains, Hamilton County, New York. 
For collecting in the field, it has been found most convenient 
