GENERAL MORPHOLOGY. 105 



liyphaB of many fungi, and even teeth and bones may 

 become infiltrated with fungus threads. 



The propagation of the fungi occurs usually by means Varieties of 

 of spores, i.e., cells, which can give rise to one or several tion. 

 germinating tubes, and thus to a new vegetative body 

 similar to the original one. In rare cases some of the 

 cells of the mycelium themselves form the spores ; as a 

 rule, however, certain hypha3 grow from the mycelium, 

 take on another form and show other conditions of 

 growth, and are termed fruit hypha3, or fruit-bearers. If 

 a large number of fruit hyphae lie together, a so-called 

 fruit body is formed, and this is more especially the case 

 in the higher fungi. The modes in which the spores 

 develop on the fruit-bearers, and the manner in which 

 they are distributed after ripening, are very diverse, and 

 these differences in fructification furnish in the main the 

 principles on which the usual classification of the fungi 

 is based. 



With regard to the development and dissemination of 

 the spores we distinguish 



a. Intercalary formation. Along the course of the 

 growing hyphae certain cells are marked off, assume 

 a somewhat distinct form, and become spores or spore- 

 bearing cells. These formations are frequently termed 

 (jcmmcc. 



b. Acrogenous segmentation. The terminal portions 

 of the fruit hyphae are separated by transverse division, 

 and act as spores. The thin stalks or fruit-bearers are 

 termed baMia. If from the ends of these hyphae thin 

 stalk-like branches proceed, on which the spores are 

 formed by strangulation, these spore-bearing stalks are 

 termed sterigmata. As to the mode in which the trans- 

 verse division of the terminal cells occurs only one spore 

 may be formed ; or a number of buds may arise at the 

 same time on the summit of the basidium; or several 

 spores may be separated one after the other from one 

 basidium. The freeing of the spores takes place either 

 by disappearance of the stalk, or by strangulation, where 

 a zone disappears, or softens in the transverse division 

 between sporo and fruit-carrier, or by being hurled away. 



