ASPERGILLUS FUMIGATUS, A. NIDULANS, A. TERREUS N. SP. 87 
through the human digestive tract. This led him to feed cultures of 
this species to a rabbit, which afterwards died. A. terreus was re- 
covered in culture from numerous portions of the intestine (Turesson, 
loc. cit., p. 20). Further studies upon the possible relation of this 
form to toxin production are necessary. 
Some experiments were made to find whether this form is an 
active inhabitant of the soil or merely present in spore form. Two 
forms of soil, a light sandy loam from Texas and a clay type from 
Indiana, were obtained from the soil fertility laboratory; a third 
sample was obtained from the greenhouses of the Arlington Farm. 
Finely divided soil to a depth of about 5 cm. was tamped into test 
tubes and sterilized. Part of the series was given fractional steriliza- 
tion in steam, the remainder 30 minutes in the autoclav at 15 pounds 
pressure. Three cc. of water were added to the light soil and 2.7 cc. 
to the heavy soil. The water was added before heating, in the case 
of the fractional sterilization, but after heating, in the case of auto- 
claving the tubes. These differences of manipulation seemed to have 
no effect upon the growth of the organisms tried. 
The test tubes of soil were inoculated by sprinkling spores on the 
surface of the soil in the test tubes. For comparison of growth, three 
strains of A. terreus, one of A. nidulans, six of A. flavus, one of A. 
clavatus, one of A. oryzae, three of the Citromyces section of Peni- 
cillium, P. pinophilum and P. luteum, were used. Each is representa- 
tive of a group of related forms repeatedly found in soil. After a 
period of approximately two months, the typical conidial masses of 
A. terreus could be seen not only upon the surface but in the open 
spaces in the sandy soil to a depth of 3 cm. The organism was re- 
covered in pure culture from the deepest areas, where growth was not 
visible, by breaking the tips of the test tubes and transferring some 
particles of soil to culture media. Although cultures showed the 
mold to be present, traces of mycelium were often very difficult to 
find by microscopic examination. Mycelia under such conditions are 
much less evident. Short zigzag hyphae are found in intimate con- 
tact with soil particles rather than richly branching mycelia ramifying 
through wide areas. Spores are produced from short stubby branches 
extending into small open spaces. Hyphae and heads under these 
conditions are not recognizable by data based upon pure culture in 
artificial media. Nevertheless, it is clear from the table that A. 
terreus and many others of these species planted upon its surface are 
