192 



CRYPTOGAMS 



315. A perithecium brok- 

 en open to show 

 the asci. 



tions are produced on the leaf surface, appearing to the 

 naked eye as minute rounded black bodies. These are 

 the perithecia "(Fig- 315) which in- 

 close the spore sacs. The perithecia 

 bear radial appendages. 



456. Aspergillus, a very common 

 fine mold on dry bread, cake, cheese, 

 preserved fruits, etc., should be men- 

 tioned here, since, though it is really 

 an Ascomycete, it would not be rec- 

 ognized as such at one stage of its 

 existence. On first appearing upon 

 the given substratum the mycelium sends up great num- 

 bers of erect branches ending in globular heads, from 

 which are produced spores in chains 

 radially arranged (Fig. 

 316). At a later stage 

 of its history the myce- 

 lium gives rise to small 

 rounded fructifications 

 inclosing the character- 

 istic spore sacs of an 



Ascomycete. In like 317 - Fruit of As P er - 



gillus, with 

 manner other members a sci (a). 



of this group are known KNY. 



to pass through two stages of develop- 



316. S^tion of the ment differing in the 

 method of spore bear- 

 ing. Periicillium, a very 

 common blue mold (Fig. 



318), is an example. 



457. The Rusts. Many Fungi un- 

 dergo remarkable transformations in the 



course of their life history. This is very 



marked in the case of the Rusts, of which 



the common Rust of Wheat (Puednia 



r/raminis) may be taken for description. 



*' . . ., J , . --t, 318. Sporophore of 



It infests the leaves and stems of Wheat, peniciiiium. 



sporophore of 

 Aspergillus. 

 KNY. 



