V] 



LABOULBENIALES 



175 



the appendages aside and take up an apparently terminal position. The 

 development is very uniform, and has been described by Thaxter in some 

 detail for Stigmatomyces Baeri. Here, the upper cell of the receptacle 

 divides into two; the lower of these remains as part of the receptacle, and 

 the upper grows out (fig. \-},6d) to form the female organ and ultimately 



Fig. 136. Stigmatomyces Baeri Peyritsch ; development of the perithecium; a. shows the two-celled 

 receptacle, a single appendage bearing five simple, endogenous spermatial organs, and the beginning 

 of the perithecium; b. — i. indicate successive stages in the development of the perithecium; the 

 trichogyne first appears in d. ; in t. spermatia are being shot out and some are attached to the 

 trichogyne; in i. two of the four ascogenous cells are shown, with the superior sterile cell above 

 them, and the primary and secondary inferior sterile cells below; after Thaxter. 



the perithecium. It divides transversely; the upper of its daughter cells gives 

 rise to the female organ, the lower divides several times (fig. 136(5), and 

 ultimately forms the double wall of the perithecium, a function fulfilled by 

 a complex of neighbouring hyphae in Ascomycetes with a richer vegetative 

 development. 



The upper cell, the initial of the female organ, divides, separating the 

 female cell below (fig. 136^) and a cell above, which divides once more to 

 form the terminal trichogyne and the subjacent trichophoric cell (fig. 136^/). 



