PERISPORIACE^L 



281 



189 _. The 8exual proceg in ErgAph 



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 Podospliwra}, and in the other genera two or more, are 

 developed. In each 

 ascus from two to 

 eight ascospores arise 

 by internal cell-for- 

 mation (//, a, Fig. 

 188). The sporocarp 

 (technically called 

 the perithecium) be- 

 comes dark and hard, acearum. a, threads of mycelium ; b" antheridium ; 

 c, carpogonium ; d, young sporocarp ; e, older sporo- 

 and from Its OUter carp. Highly magnified. After CErsted. 



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 

 ' other organs, which bear small spore-like 

 en; the appendages of bodies, but whose function is not certain 



the perithecmm are , . 



curved in a circinate ly KHOWO. TllCSC Organs, whlCtl are 



manner at their free ex- ' ... - 



tremities. After cooke. known as pycnidia, 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, Avhich is common on articles of food, as bread, 

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



