Mar., 1921] HAENSELER GROWTH OF ASPERGILLUS NIGER 
doubled, as is clearly shown by the ratios in the last column of table 3. 
The ratios derived from the yield values of the cultures in series 3 and 5 
which do not show this relation are indicated in table 3 in bold-face type. 
Effect of Varying the Salt Proportions on the Growth of 
Aspergillus nicer 
To facilitate the comparison between the yields with respect to the 
variations in the salt proportions, the yield values are presented in graphic 
form in the triangular diagrams of figures 3 and 4, in which each culture 
occupies a definite position according to the proportions of the salts it 
contains. In these triangles the individual cultures are numbered according 
to the row in which they occur (Ri, R2, R3, etc.) and according to their 
position in the row (Ci, C2, C3, etc.) According to this triangular diagram 
(6) the osmotic proportions of the salts in any culture are indicated by its 
position on the triangle. The partial volume-molecular concentrations 
corresponding to these proportions are found in table i or in table 2. The 
actual dry weight of fungus derived from each culture is given just opposite 
the point of the triangle representing that culture. The areas on the 
triangles including the high, medium, and low yields are separated by dotted 
lines. The area at the lower right of each triangle includes the cultures 
giving the highest nine yields, while the cultures giving the lowest nine 
yields are embraced in the area lying along the left margin of each triangle. 
The central region on each triangle includes the cultures giving medium 
yields. In series 5, however, the three cultures at the extreme lower right 
of the triangle fall into the medium-yield area. 
Considering first the efi"ects of changing the partial concentration of 
KH2PO4 and MgS04, it will be observed in series i (fig. 3) that all the Ci 
cultures (on the left margin of the triangle) gave approximately the same 
yields. All these cultures contain the same amount of calcium nitrate 
but differ widely in their proportions of KH2PO4 and MgS04. The partial 
concentration due to each of these latter two salts varies from i/io to 8/10 
of the total salt concentration, but in spite of the wide differences in the 
partial concentrations due to these two salts, all the cultures show approxi- 
mately equal yield values. This same indifference of the fungus to changes 
in the partial concentration of KH2PO4 and MgS04 is shown by all cultures 
in which these two salts are the only variables. The Ci cultures of any one 
series have very nearly equal yield values. Likewise, all the C2 cultures 
or C3 cultures, etc., of any particular series gave approximately equal 
yields. In series i, where the total concentration is only 0.5 atmosphere, 
or in series 3, with a total concentration value of 4.2 atmospheres, the fungus 
is apparently indifferent to the wide variations in the proportions of KH2PO4 
or of MgS04. Thus all these series point to the conclusion that within 
wide limits neither KH2PO4 nor MgS04 tends either to stimulate or to 
inhibit growth in Aspergillus niger. There is no evidence of a physiologically 
