CHAPTER VI.—PHENOMENA OF GERMINATION. 347 
The behaviour of Saccharomyces Cerevisiae, ıhough not strictly belonging to 
this connection, may be adduced to show that Fungus-spores are capable of bearing 
very low degrees of temperature, for some only of its cells, according to Schumacher’, 
were killed by a temperature of —113.75° C., while others lived and retained their 
powers of growth. 
On the other hand, many spores, especially those that are long-lived, can endure 
extremely high temperatures without losing their vitality. Some observations show 
that the length of the time to which they are exposed to the heat is an important 
element in the case. The dry spores of a certain number of Fungi are not killed by 
a heat which considerably exceeds 100° C. According to Nägeli it may be said that 
a temperature of 130°C. is necessary to secure their destruction. But the death-point 
of the spores of Fungi is often much lower than this in water or watery vapour, and 
it has not been shown that any can under these circumstances survive a temperature 
of 100° C. 
According to H. Hoffmann the dry spores of Ustilago Carbo and U. destruens 
support unharmed a temperature of from 104° to 128°C.; the spores of U. Carbo are 
killed in a chamber filled with vapour at a temperature between 58°.5° and 62” C., 
those of U. destruens by a temperature of from 74° to 78° C. in the space of an hour, 
and by one of from 70° to 73° C.in 2 hours. Tilletia Caries, on the other hand, will 
bear according to Schindler a temperature of 95° C. if dry, but not more than that. 
According to Payen* the spores of a mould found in bread, Oidium aurantiacum, can 
endure a temperature of 120° C.; at 140° C. they were discoloured and killed. 
Pasteur’s researches showed that the spores of Penicillium glaucum remain 
unaltered in dry air at a temperature of 108°C. Many, but not all, lose their power of 
germination at 119° to 120°C.; all lose it very quickly if the temperature is raised to 
between 127° and 132°C. The limit is similar in ‘ Ascophora elegans’ (a species of 
Mucor). Similar results were obtained from experiments on some spores of uncertain 
origin mixed with dust, among which Botrytis cinerea, P. (gonidia of Peziza Fuckeliana) 
or a closely allied form may be certainly distinguished; these bore a temperature 
of 120°C. Spores suspended in a fluid which was heated up to 100° C. were always 
killed in Pasteur’s experiments. 
Against these statements must be placed the results of Tarnowsky’s researches 
communicated by Sachs‘, according to which spores of Penicillium glaucum and 
Mucor stolonifer when heated in air to a temperature of from 70° to 80° C. during 
1-2 hours very seldom germinated, and were killed by a temperature of from 82°C. to 
84°C.; they lost all vitality when warmed in a fluid up to from 51°to 55°C. We may 
just mention some older statements of J. Schmitz* on this subject, which certainly 
stand much in need of investigation. 
The foregoing statements show that the spores of the Fungi are similar in 
character to the organs with analogous functions in other plants. They afford 

1 Sitzgsber. d. Wiener Acad. 70, 1 Abth. Juni, 1874, where other literature is cited. See also 
Pfeffer, Physiol. II, 438. 
2 Compt. rend. XXVII, p. 4. 
® Lehrb. Auflage 4, p. 699. 
* Verhandl. d. naturh. Ver. d. Rheinlande, II (1845). 
