CHAPTER VII.— PHENOMENA OF VEGETATION. — SAPROPHYTES. ^jj 



experiment does actually occur among the natural conditions is a distinct question 

 requiring a special enquiry for its determination, and the observed fact is as little 

 altered by any experimental result in the present case, as in the instance referred to 

 above of land-plants which thrive when grown in water. 



3. SAPROPHYTES. 



Section C. By far the larger part of the Fungi, according to our present 

 knowledge, are saprophytes ; our fifth chapter has already shown that this is the 

 case. 



We at present have only an imperfect acquaintance with life-conditions and adapta- 

 tions in these species, yet there must be a great variety of them in all the many cases 

 described in the books, in which a particular species of Fungus is always actually 

 found on a distinct, and, as it may be termed, a specific substratum. Indications of 

 this fact, to which attention has been already called on page 351, are afforded by the 

 Fungi which grow on the dejecta of warm-blooded animals, dung, feathers, &c. 



The spores of these species, as was first shown by Coemans * in the case of 

 Pilobolus, easily find their way from their regular places of origin to the food of the 

 animal, are provided with the necessary conditions for germination in the intestinal 

 canal, and complete the development which they have commenced there on or in the 

 voided dejecta. Experiments in cultivation such as may be carried out without 

 difficulty show that other methods beside this one are not excluded, at least in the 

 case of many species which live on dung (Mucor, Pilobolus, Sordaria, and some 

 species of Coprinus). 



The observations of Pasteur 2 and E. Hansen 3 have brought to light some 

 peculiar arrangements in the life of the Saccharomycetes which excite alcoholic 

 fermentation when growing spontaneously, though these arrangements are not yet 

 quite intelligible. According to the careful investigations of the latter writer Saccharo- 

 myces apiculatus appears in the open air on garden fruits containing sugar as soon as 

 they are ripe, finding nourishment and growing on them, especially if the outer rind is 

 broken. It very rarely or never occurs on the fruit before it is ripe, and if it has 

 shown itself on early-ripening fruits, such as currants, gooseberries, or cherries, it is 

 wanting on others which ripen later, plums and grapes for instance, as long as they 

 are still green. In the interval between two periods of ripening of the fruit, even in 

 winter, it is found capable of development in the soil beneath the plants whose ripe 

 fruit it attacks, and very rarely in any other place. Distinct spores are not known in 

 this species, only the vegetative cells produced by sprouting. The actual life-history 

 of the plant is therefore very simple ; it is easy to conceive how it finds its way with or 

 from the ripe fruit by the aid of wind or rain to the ground and is carried back with 

 dust from the ground to the fruits, and its living through the winter in the ground is 

 not at all surprising ; but it has still to be explained why it is so rarely or never found 

 on green fruit or in some other place. Pasteur 4 had shown before that cells of 



1 Monogr. d. Pilobolus. See before on page 158. 



2 Etudes sur la biere, especially at p. 155. 



3 Meddelelser fra Carlsberg Laboratories I, Resume francais, p. 159. 

 1 Etudes sur la biere. 



j 



