PERISPORIACE^E. 281 



carpogonium becomes divided in such a way that from one 

 portion of it an inner layer of cells is formed in contact with 

 the outer envelope described above. From the remaining 

 central part of the carpogonium one ascus (in Sphcerotheca 

 and Podosphcera), and in the other genera two or more, are 

 developed. In each 

 ascus from two to & 



eight ascospores arise 

 by internal cell-for- 

 mation (II, a, Fig. 

 188). The sporocarp 

 (technically called 

 the perithecium) be- 



COmeS dark and hard acearum. a, threads 01 mycelium ; 6, anthcridium; 

 c, carpogonium ; d, youm' sporocarp ; e, older sporo- 

 and from Its Ollter carp. Highly magnified.-After OSrsted. 



cells there grow out long filaments (technically known as 

 appendages), which are usually septate, and of a particular 

 shape in each genus ; thus in Podosphcera and Microsphcera 

 they are dichotomously branched ; in Phyllactinia they are 

 straight and needle-shaped ; in Uncinula they are curved 

 regularly at their tips (Fig. 190), while in the other genera 

 they are tortuous, and simple or irregu- 

 larly branched. The perithecia remain 

 during the winter upon the fallen and 

 decaying leaves, and finally, by rupturing, 

 permit their asci, with their contained 

 ascospores, to escape. 



375, There are usually present some 

 hcim$a *ddun- ^ ner organs, which bear small spore-like 

 i /' the appendages of bodies, but whose function is not certain- 



the perithecium are 



curved in a circinate ly known. These organs, which are 



manner at their free ex- J t 



tremities. After cooke. known as pyciiidia, are clavate, ovate, or 

 nearly spherical in shape ; the bodies they contain (the so- 

 called pycnidio-spores) in their cavities are usually oblong 

 or elliptical. 



376. In the genus Eurotium (composed of saprophytes) 

 the conidia are produced in a slightly different way. The 

 mycelium, which is common on articles of food, as bread, 

 pastry, preserved fruit, etc., and on poorly dried specimens iu 



