RELATION BETWEEN VEGETATIVE VIGOR AND REPRODUCTION 543 
than that out of o.oi percent peptone, as was to be expected. After 
being washed the myceha from these solutions were transferred to 
water at the laboratory temperature, about 18° C. Sporangia were 
readily produced and Table III shows the relative number of sporangia 
and oogonia from mycelia grown in various culture media. 
With the exception of the mycelium out of 2 percent peptone, 
there is roughly an agreement between the mass of mycelium and 
the number of sporangia formed, and it is clear that a poorly nourished 
mycelium will not make many sporangia. The addition of salts to 
the peptone not only increased the vegetative growth but also the 
number of sporangia, a result not secured with sugar. So far as could 
be observed the mycelium from the 0.5 percent peptone developed 
as many sporangia as did that from i percent or from 2 percent, while 
that from o.i percent showed a falling off. This would seem therefore 
to be the critical concentration, below which a still more decided 
falling off in the number of sporangia is to be noted. The same 
mycelium developed both sporangia and oogonia in water, and the 
Table IV 
Achlya racemosa. Mycelia Grown Seven Days in Media Under Column 2. Trans- 
ferred to Water at 24.° 
2 
3 
4 
5 
6 
7 
8 
I 
Media. 
Sporangia, 
Spo- 
rangia, 
Oogonia, 
Oo- 
gonia, 
Oo- 
gonia, 
Remarks. 
I Day. 
2 Days. 
I Day. 
2 Days. 
5 Days. 
I 
Peptone 0.1%, 
sucrose 1%, 
salts 0.1% 
Few 
0 
II 
Ill 
Ill 
Many without 
I 
oospores. 
2 
Peptone 2% 
I 
I 
I 
II 
Oogonia larger 
than in No. i 
and well filled. 
3 
Peptone 1% 
o-I 
O-I 
II 
II 
III 
Oogonia large, 
mostly with one 
Peptone 0.5%. .. . 
I-II 
II-III 
III 
large oospore. 
4 
0 
III 
5 
Peptone 0.1%. .. . 
Very few 
0 
II-III 
III 
III 
As in number 3. 
8 
Peptone 0.1%, 
salts 0.1% 
0 
Rare 
II-III 
III 
III 
Some empty 
Peptone 0.1%, 
oogonia. 
9 
salts 0.05%. . . . 
0 
0 
II-III 
III 
III 
About 20% empty. 
10 
Peptone 0.1%, 
sucrose i % . . . . 
o-I 
0 
III 
III 
III 
About 30% empty. 
II 
Peptone 0.1%, 
sucrose 0.05%. . 
0 
0 
III 
III 
III 
About 50% empty. 
