Physiologie 
29 
branches of the hermaphrodite and branches of the (—) race under test, 
and vice versa, which lead one to consider the (—) race male and the 
(+) race female. C. J. Humphrey (Madison, Wise.). 
SEAVER, E. J. ? Studies in pyrophilous fungi. III. The viability 
of the spores of Pyronema (Bull. Torr. Bot. Club 1912, 39, 
63—67; 1 pi.). 
It was found that spores of Pyronema omphalodes , which had been 
in the herbarium for three years germinated readily. This was against 
expectations for the spores are thin walled and will germinate immediately 
on being released from the ascus, without any resting period. The author 
gives his directions for preparing material of Pyronema for class pur¬ 
poses: ‘‘Heat good rich, unfertilized, garden soil by placing it in pots or 
other receptacle. The heating can be accomplished by steam or dry heat 
in an autoclave or sterilising oven. If dry heat is used run the tempe¬ 
rature up to 150—170° C. If neither autoclave nor sterilising oven is 
available, bake in an ordinary oven for an hour or more at ordinary 
baking temperature. Cool and water with tap water. Plant the spores 
and place the pot under a bell jar. Growth of mycelium should be 
abundant in two or three days at room temperature; sex organs should 
appear in about a week and nature ascocarps a few days later. 
When through with the study of plants, scrape off the old ascocarps 
together with a little dirt, place them in an envelope and keep dry until 
they are desired for study the next year, then prepare substratum and 
plant as before.“ J. Ramsbottom (London). 
POLLOCK, J. B., An optimum culture medium for a soil fungus 
(Science, N. S. 1913, 37, 386—387 [7. Mar.]). 
Sixteen carbon compounds were tested, using a species of Mycelio- 
phthora. Five substances were tested as a nitrogen source. Magnesium 
sulfate was used to supply Mg and S, and mono-potassium phos¬ 
phate to supply P and K. CaN0 3 at a concentration of 1 / 250 M proved 
best for N; the phosphate was good at 1 / 10 to 1 / 100 M concentration; of 
carbon compounds maltose was decidedly the best when NH 4 N0 3 was 
used, but saccharose proved best with CaN0 3 . Saccharose may be 
procured in a very pure form as rock candy and is far more pure than 
C. P. maltose or dextrose. The following is given as the optimum medium 
for the fungus in question: 
Saccharose. -L M. 
/ o 
Calcium nitrate. 1 / 250 M. 
Monopotassium phosphate . . l / 1Q — L / l00 M. 
Magnesium sulfate. Viooo M. 
C. J. Humphrey (Madison, Wise.). 
EWERT, R., Weitere Studien über die physiologische und fungi¬ 
cide Wirkung der Kupferbrühen bei krautigen Gewächsen 
und der Johannisbeere (Zeitschr. f. Pflanzenkrankh. 1912, 22, 
255—285). 
Versuche mit Kartoffeln, Radieschen, Buschbohnen, Oxalis 
esculcnta und Stachys tuberifera haben gezeigt, daß die Anwendung von 
Kupferbrühen keine vorteilhaften Folgen für die Lebenstätigkeit der Pflanze 
hat. Bei Anwendung von concentrierten Brühen wurde das Ernteergeb- 
