278 INTEODtrCTION TO CKYPTOGAMIC BOTANY. 







Fig. 64. 



a. Fulcra and asous, -with sporidia of Uiicinvla spiralis, Berk, and 

 Curt. 



b. Peritliecium, with its numerous fulcra and ascus, of Erysiphe densa, 

 Berk, and Curt. 



c. Ditto of Microsphcera semitosta, Berk, and Curt. 



d. Fiilcra of Uncinula adunca, L6v. 



e. Ditto of Microsphcera Mougeotii, L6v. 



All more or less magnified. 

 From specimens communicated from tiie United States, by Eev. M. A. 



Curtis. 



3. Sph^riacei, Ft. 



Perithecia free or immersed in a woody or variously consti- 

 tuted stroma, opening by a distinct punctiform or short linear 

 aperture. Asci mostly springing from the walls, persistent. 



284. We come now to an immense group of Fungi, com- 

 prising at the least a thousand good species, and possibly 

 double that number. As at present limited, the species are 

 doubtless multiplied beyond all necessity; but an attentive 

 study win at once prove that they must be very numerous. 

 The old genus Spluerla (Fig. 65) is now broken up into a large 

 number of genera, but the distinctions are difficult, and by no 



