540 
ADRIAN J. PIETERS 
Livingston ('05) was then tried and it was found that this gave uni- 
form and satisfactory results. Out of the many records available on 
this point only one table will be given to show the effect of the water 
on the formation of sporangia. Tap water was also found to be 
quite as unsatisfactory as distilled water. 
Table II 
Achlya racemosa, Grown Three Days in Culture Solution N^; Transferred to Water 
for the Formation of Sporangia 
I 
2 
3 
4 
Sporangia in 12 Hrs. 
In 24 Hrs. 
48 Hrs. 
Distilled water from 
chemical laboratory 
Distilled water shaken up 
with carbon black 
0, Mycelium dying. 
I -f discharged. 
I + discharged. 
Few formed, none 
discharged. 
II -f discharged. 
Dead. 
Ill 
III 
Few discharged. 
Ill 
Exhausted. 
Exhausted. 
Some gemmae. 
Exhausted. 
Distilled water re-distilled 
and filtered through car- 
bon black 
Double distilled rain water . 
Double distilled rain water 
filtered through carbon 
black 
Similar results were secured with other species. All species are 
not equally sensitive to the water, however, but all gave more uniform 
results when water purified with carbon black was used. In all the 
following experiments, therefore, whenever the ability of a mycelium 
to produce sporangia was to be tested purified water was used. 
To determine whether the use of this carbon black would intro- 
duce an unknown food element into the water some carbon black was 
carefully washed by shaking it up with a small quantity of water, 
which was then filtered off. Mycelium was transferred to this water 
but in no case did any growth result, though sporangia were at once 
formed showing that the water contained no food. 
Culture media. — With the exception of pea extract, only synthetic 
media were used. Many of the various natural media, such as ants' 
eggs, larvae, and so forth, might have been used and might have 
given interesting results. It was desired, however, in the first place 
to use, so far as possible, only media of known composition; and in 
^ This solution contained o.i percent peptone, i percent sucrose and o.i per- 
cent salts. 
