344 DIVISION III-—MODE OF LIFE OF THE FUNGI. 
of germination for a short time only after completing their brief period of swarming 
and die if the conditions are unfavourable to germination. But the diplanetic spores 
in these groups (see pages 108, 143) are to some extent exceptions to this rule, since 
they may continue alive and unaltered for days and weeks, perhaps longer, after 
entering upon the transitory period of rest, if the conditions required for their further 
development, especially a sufficient supply of oxygen, are excluded. Further de- 
velopment begins if they are placed in fresh water containing oxygen, and first of 
all the second stage of swarming. 
But many spores of this first category, belonging to Fungi which do not live in 
water, retain their vitality and power of germination for a long time, if they are 
protected and kept in an air-dry state. 
It has been proved that the spores of many common Fungi will remain alive for 
a period varying 1-2 years; for example the ascospores of Penicillium glaucum have 
germinated when two years old, the gonidia after 13-13 years; the spores of 
Coprinus stercorarius! when more than 1 year old, the gonidia of Aspergillus niger 
when of the same age, of Sordaria curvula after 28 months, of Botrytis Bassii and of 
allied forms of Isaria after 1-2 years, of Mucor stolonifer after t year. ‘The gonidia 
of Phycomyces nitens, a species nearly related to Mucor Stolonifer, is a good 
example of specific and individual variation. Van Tieghem? found that they hardly 
retained their vitality for 3 months, and I once observed the germination of gonidia 
which were 10 months old, while others had lost their vitality after the space of 1 
month. 
The resting-spores of some Ustilagineae are very long-lived according to 
Hoffmann and v. Liebenberg*; the latter observer found the spores of Tilletia Caries 
from a herbarium specimen capable of germination after 8} years, those of Ustilago 
Carbo after 74 years, of U. Tulasnei and Urocystis occulta after 64, of Ustilago 
Kolaczeckii, U. Crameri and U. destruens after 53 years, of U. Rabenhorstiana 
after 34 years. In some of the forms here mentioned, as U. Carbo, the maximum 
of possible duration appears to be given; in others as Tilletia Caries the vitality 
may continue beyond the time specified, which is given for the oldest material at 
command, and this showed such active power of germination that it may be assumed 
that still older spores would have retained the power. 
Gonidia of Aspergillus flavus * proved in one case to be capable of germination 
after having been kept in a dry state for 6 years, those of A. fumigatus ® for as many as 
10 years. 
Well-known examples of spores which require to go through a period of 
rest before they are capable of germination are found in the oospores of the Pero- 
nosporeae and most Saprolegnieae, the zygospores of the Mucorini, the organs 
described above as resting-spores in the Chytridieae, Protomyces, and other forms, 
the teleutospores of most Uredineae—with the exception however of Leptopuccinia, 

1 Brefeld, Schimmelpilze, II, 76; III, 15. 
? Van Tieghem et Le Monnier in Ann. d. sc. nat. ser. 5, XVII, 288. 
* Hoffmann, in Pringsh. Jahrb. II, 267.—v. Liebenberg, Ueber d. Dauer d. Keimkraft d. Sporen 
einiger Brandpilze (Oesterr. Landw. Wochenblatt, 1879, Nr. 43, 44). 
* Brefeld, Schimmelpilze, IV, p. 66. 
> Eidam, in Cohn’s Beitr. z. Biolog. III, 347. 
