PART II 



PHYSIOLOGICAL RELATIONS 



CHAPTER III 



GERMINATION STUDIES 



CLARK, J. F. On the Toxic Effect of Deleterious Agents on the Germination 



and Development of Certain Filamentous Fungi. Bot. Gaz. 28 : 289- 



327, 378-404- 1899- 

 Duggar, B. M. Physiological Studies with Reference to the Germination of 



Certain Fungous Spores. Bot. Gaz. 31 : 38-66. 1901. 

 Ferguson, M. C. Germination of the Spores of Agaricus campestris and 



Other Basidiomycetous Fungi. Bur. Plant Ind. U. S. Dept. Agl. Built. 



16: 1-43. pis. 1-3. 1902. 



Requirements for germination. With regard to their require- 

 ments for germination, the spores of fungi show very marked 

 differences. It may be possible to group the fungi in three 

 categories, based upon their minimum requirements, although 

 it is very probable that the limitations of these classes may 

 not be fixed with any degree of definiteness. These classes are 

 as follows : 



1 . Those which may germinate in moist air or in water. 



2. Those which require a nutrient solution. 



3. Those which require a special stimulus. 



Where the spore germinates in moist air or in distilled water it is 

 merely the absorption of water, under external conditions favorable 

 for growth, which suffices to give the necessary incitation. In other 

 words, the spore is then undoubtedly provided with its own food 

 material. Many parasitic fungi evidently belong to this class. No 

 nutrient substance is known to enhance the germination of spores 

 of the Uredinales, Peronosporales, and some other obligate parasites. 

 This statement is necessarily put in this form on account of the 

 fact that many observers have employed ordinary tap water in their 



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