392 



BOTANY 



exposed on their upper surface (Fig. 332). The different groups exhibit great 

 diversity as regards the manner of development of their fructifications. 



'Flo. 331. I'czlza aitrantiaca. 

 (After KKOMBHOI.Z, nat. size.) 



Fio. 332. hichii'ii imlfherrima. Aixjthecium ruptured, 

 showing old and ynimx asri U-twecn tin- paiajihyses. 

 (After WOROXIN, from v. TAVEL.) 



Fio. 333. Pyroiifma confluens. A, Rudiment of an apothecinm, cimsistin.; of three oogonia (og), 

 with tricho^ynes (t) and three antheridia (a). B, Fusion of the anttiei idium and the tip of the 

 trichogyne. (', The basal-wall of the trichogyne having been absorbed, the male and female 

 nuclei are ground in the centre of the ooKonium. D, Sejaration of the ootfonium from the 

 tricliox'.vne by means of a new jmrtition wall. Formation of the ascogenous filaments (as/). K, 

 Longitudinal section through a youn- ajujtlieciuin. u.; AMM. (After R HARPER. A, K 

 x about 150, B-D x about 300.) 



The great majority of the Discomycetes, of which the genus Pezizti may serve 

 as a type, grow on living or dead vegetable substances, especially upon decaying 



