1901 | GERMINATION OF SPORES 55 
per cent. in the MgSO,. Water was then added to these cultures 
until the liquid was reduced tenfold in concentration. A second 
examination after the lapse of two days showed little or no 
increase of germination in the original 10 and 20 per cent. 
KNO,, but an increase to about 25 per cent. in the 5 per cent. 
solution, and a similar increase in the 5 and 10 per cent. MgSO,,. 
In the culture containing 20 per cent. MgSO,, the increased 
_ germination and the amount of growth was greater than in any 
other. 
EFFECTS OF TEMPERATURE AND OXYGEN SUPPLY. 
As previously mentioned, Heald found that fern spores kept 
at high temperature were incited to germination as by light, but 
a longer period of time was required and the response less uni- 
form. In general I have found very little difference between 
the germination in water of fungi at 25° C. and at temperatures 
nearer the maximum. At 32° C. there is some increase in the 
germination of Aspergillus flavus in hanging drop, but not in 
flask cultures. The former might well be due to other conditions 
than to any augmentation from the higher temperature. On 
nutrient solution Coprinus fimetarius was slightly benefited by the 
Same temperature. Such forms as Coprinus comatus, C. micaceus, 
Boletus sp., and Urocystis anemones could not be incited to germi- 
nation at higher temperatures when no germination occurred at 
25°. Botrytis and Phycomyces were both injured at the tem- 
perature of 32° C., Botrytis failing to germinate on water, and 
Phycomyces giving a slight growth at the bottom of the. liquid. 
Changes of temperature from 28° to 32° C. and vice versa did not 
materially affect the germination of Aspergillus and Sterig- 
Matocystis. After experiments of various kinds with the 
aecidiospores of Puccinia graminis, Eriksson and Henning’ found 
that the best results were secured by placing the spores for 
a time on melting ice, and then sowing them on water. The 
next best results were obtained when the spores were soaked in 
water at 3° C. for three hours, and then sown at room temperature. 
*9ERIKSSON and HENNING: Die Getreideroste, 71. 1896. Stockholm. 
