372 



FUNGI 



shaped pseudo-parenchymatous exciple is formed, the margin of which 

 reaches the surface. The interior of this basin is then soon filled with 

 upright paraphyses like those which originally attained the surface. The 

 turns of the original coil become unloosed, and eventually there are 

 given off from it ascogenous hyphae which, after branching in the sub- 

 hymenial zone like those of Ascobolus, finally produce successive asci 

 in the mature apothece. 



In Physma Massal. the carpogone is produced from the hyphae 

 which form the wall of the antherid, and the trichogyne rises to the 

 surface outside the wall. Eventually the paraphyses and asci are pro- 

 duced in the place formerly occupied by the sterigmata of the antherid, 



FIG. 308. Leptogium microphyllnm Ach., young apothece in section, h, hyphae ; g, algal cells ' 

 a, thalloidal exciple ; b, exciple proper ; c, hypothece. The apothece is filled with paraphyses, 

 among which may be seen bladder-shaped ascogenous hyphae with three young asci ( x 530). (After 

 Stahlj 



and the antherid is thus transformed into the sporocarp. The species 

 of Collema (Ach.) have no acrospores, and resemble in the course of 

 their life -history Ascobolus, Pyronema, &c. For structure of lichen- 

 thallus, see p. 318. 



9. POLYSTIGMA (Pers.) is a genus of parasitic fungi bearing a striking 

 resemblance to the Collemaceae in its sexual reproductive apparatus. 

 Antherids and pollinoids are formed differing in no material respect 

 from those of the Collemaceae the pollinoids being in this case more 

 thread-like and bent. The genesis of the sporocarp is characterised 

 here, however, by the formation of a fundamental coil of hyphae smaller 

 than the thallus-hyphae. The carpogone appears among these, consisting 

 of a spirally-wound hypha of two or three turns, with broad short cells. 



