DIVISION III. MODE OF LIFE OF THE FUNGI. 



CHAPTER VI. Phenomena of Germination. 



1. CAPACITY OF GERMINATION AND POWER OF 

 RESISTANCE IN SPORES. 



Section XCV. The greater number of known spores in the Fungi, the word 

 spore being taken in the meaning assigned to it on page 128, are capable of 

 germination from the moment that they are ripe. In a smaller number of known 

 forms this is not the case; the spores do not germinate till after they have passed 

 through a period of rest which follows upon their maturity. 



Examples of the first kind, that is, of spores which germinate immediately 

 after maturity, are all ascospores, most spores of the Hymenomycetes, the majority 

 of the forms known as gonidia, the oospores of some Saprolegnieae, as Achlya 

 spinosa, A. apiculata, and Aplanes (section XL). 



Some spores are capable of germinating even before maturity, that is, before 

 they have reached the condition which according to empirical rules indicates 

 maturity (see page 59). The gonidia of the Saprolegnieae, for example, may omit 

 their regular swarm-cell period in cultivated specimens and germinate beneath the 

 cover-glass 1 ; the ascospores of Sordaria fimiseda in Woronin's 2 experiments 

 showed themselves capable of germination long before the completion of their 

 definitive membrane and their discharge from the ascus, and similar cases are not 

 unfrequent among the Ascomycetes. 



The period of time during which spores of this category retain the power of 

 germination, where the conditions are unfavourable to germination and the spores 

 are not subjected to any serious injury, varies in different species and individuals and 

 according to the form of the spore. It is short in the comparatively watery and 

 turgescent gonidia of the Peronosporeae, and in the uredospores, aecidiospores, and 

 sporidia of the Uredineae, lasting where the spores are not quite dried up for a few 

 weeks, seldom for a few months, and coming to an end, as far as we know at 

 present, with the summer in which the spores were matured. Gonidia, for example, of 

 Cystopus candidus which were not perfectly air-dry continued capable of germination 

 6-8 weeks, those of Phytophthora infestans for 3 weeks, perfectly air-dry gonidia 

 of the latter species (caught on glass-plates) lost their power of development in 24 hours. 

 Similar results were obtained in the case of the spores of the Uredineae mentioned 

 above. The ripe swarm-spores of the Saprolegnieae and Peronosporeae remain capable 



1 Thuret in Ann. sc. nat. ser. 3, XIV, t. 22. 

 3 Cited on page 262. 



