352 DIVISION III.—MODE OF LIFE OF THE FUNGI, 
of this work (page 240) altogether out of the question, we may quote here, as 
examples only, the basidiospores of most Gastromycetes (Phalloideae, Lycoperdaceae, 
Hymenogastreae), and the ascospores of Tuber, Elaphomyces, and allied genera,—organs 
which in contrast with the more or less doubtful spermatia are quite certainly 
homologous with allied forms which germinate readily. To these may be added 
the zygospores of Mucor stolonifer, Brefeld’s Mortierella Rostafinskii. The germination 
of Agaricus campestris also has never been certainly observed’. The number of cases 
of this kind has gradually diminished, the more it was recognised that the conditions 
of germination or adaptations might vary from one species to another and the more 
these conditions were ascertained in particular cases. This must be considered in judging 
of unsuccessful experiments in germination, and may lead us to expect success from 
further investigations in cases where it has hitherto been wanting. On the other hand, 
phenomena such as those pointed out on page 332 in connection with Sphaerobolus must 
not be disregarded. 
The sporocarps of Erysiphe which were closely studied by Wolff? show that in 
germination as elsewhere adaptations may occur which deviate considerably from those 
ordinary cases of adaptation on which our views are apt to be founded. These arrive 
at maturity, that is, separate from the nutrient substratum with the termination 
of the period of vegetation. At this time the asci are formed inside them and in 
most species the spores also are formed in the asci, but in some (E. graminis, E. 
Galeopsidis) no spores are yet formed. In this condition the sporocarp enters upon 
its winter’s rest. When this is over and the sporocarp is placed in water, the spores 
are formed and ripen in E. graminis and E. Galeopsidis, in other species, as E. communis, 
they ripen only; then the spores are at once discharged from the sporocarp which 
bursts by the swelling of its contents, and the spores germinate. In this case therefore 
the mature sporacarp hibernates, provided, as minute investigation shows, with reserve 
material for the subsequent formation of the spores, and the spores, even those which are 
apparently and which were formerly supposed to be ripe before hibernation, do not really 
mature and acquire the capacity for germination till after the winter rest is over. In 
contrast to this proceeding most other homologous sporocarps form mature spores | 
with the power of germination either without passing through a resting stage or before 
they enter it, or else they become dormant before the formation of the asci when they 
are in form like a sclerotium or xyloma. It is not yet ascertained whether there are 
not species even of Erysiphe which dispense with a period of rest. Tulasne’s* account of 
E. guttata seems to point in this direction. 

CHAPTER VII. PHENOMENA OF VEGETATION. 
1. GENERAL CONDITIONS AND PHENOMENA. 
Section XCVII. Fungi resemble all other plants in the main features of 
their organisation and material composition ; it may be assumed therefore beforehand, 
and the assumption is confirmed by experience, that the most general conditions of 
vegetation are the same in both classes, which may therefore in general terms be said 
to be dependent in the same manner on light, heat, gravitation, and the chemical 

1 See Nylander, Flora, 1863, p. 307. 
? As cited on p. 294. See above, pages 76 and 202. 
® Carpol. I. 
