RELATION BETWEEN VEGETATIVE VIGOR AND REPRODUCTION 56 1 
. In this series the small weight of the mycelium out of peptone- 
levulose is difficult to account for. Unfortunately the duplicate flask 
failed of inoculation, and the weight represents but one culture in- 
stead of an average of two as in the other cases. The number of 
oogonia on the mycelium out of levulose-peptone was however again 
greater than that on mycelia out of other solutions containing sugars 
and was practically the same as that out of i percent peptone. Mal- 
tose was freely used for vegetative increase but the mycelium out of 
maltose-peptone did not develop a large number of oogonia. 
At the same time that the cultures recorded in Table XVI were 
set up, another series was planned to determine what effect salts added 
to the peptone alone, or to peptone and sugars, would have on the 
vegetative growth or on the number of oogonia. The time available 
was insufficient for repeating this experiment and the results are 
offered as suggestive rather than as proof of the conclusions that 
seem to be warranted. 
Table XVII gives the results of this experiment. The mycelia 
out of the solutions marked with an asterisk were overheated during 
the experiment, and the number of oogonia formed cannot be regarded 
as fairly representing the capacity of each mycelium to produce 
oogonia. The figures have, therefore, been omitted. 
It would appear from the record that the addition of phosphate 
salts, and, to a much less degree, potassium nitrate, stimulates growth 
while calcium nitrate, potassium sulphate, and magnesium sulphate 
have no marked effect. The only conclusion that seems fully justified 
by the somewhat uncertain results of one trial, however, is that 
phosphates exert a marked effect both on the amount of dry matter 
and on the number of oogonia produced. Comparing numbers 
5 to 10 with 16 and 17 it will be seen that while in the latter the use 
of phosphates with peptone alone has increased the weight materially 
over that when peptone only was used (21), it still falls short of the 
weight of the mycelia out of the solutions containing sugar, peptone 
and phosphates. The number of oogonia produced on the various 
mycelia is, however, of the same order of magnitude in all cases, in 
which a phosphate was used, and this number is much larger than 
that obtained when other salts were used (compare 19 and 20). 
The conclusions seem warranted, therefore, that in the case of 
5. monoica also there is no necessary relation between weight of 
mycelium and the number of oogonia that may be produced; that 
