62 FUNGI. 



catecl, and these are no longer regarded so much, as species of 

 Hendersonia or Diplodia as the pycnidia of Splueria. Other and 

 more minute perithecia, containing minute, slender stylospores in 

 great numbers, formerly classed with Aposphceria, Phoma, &c., but 

 are now recognized as spermogonia containing the spermatia of 

 Spliarice. How these influence each other, when and under 

 what circumstances the spermatia are instrumental in impregna- 

 tion of the sporidia, is still matter of mystery. It is clear, how- 

 ever, that in all these conidia, macrospores, microspores, and 

 some spermatia, or by whatever names they may be called, there 

 exists a power of germination. Tulasne has indicated in some 

 instances five or six forms of fruit as belonging to one fungus, 

 of which the highest and most perfect condition is a species of 

 SpTiaria. 



PEKISPORIACEI. Except in the perithecia rupturing irregularly, 

 and not dehiscing by a pore, some of 

 the genera in this group differ little in 

 structure from the Spliceriacei. On the 

 other hand, the Erysiphei present impor- 

 tant and very interesting features. They 

 occur chiefly on the green parts of grow- 

 ing plants. At first there is a more or 

 less profuse white mycelium.* This 

 FIG. 36. Uncmuia adunca. gives rise to chains of conidia (jOidium), 

 and afterwards small sphseroid projections appear at certain 

 points on the mycelium. These enlarge, take an orange colour, 

 ultimately passing into brown, and then nearly black. Exter- 

 nally these perithecia are usually furnished with long, spreading, 

 intertwined, or branching appendages, sometimes beautifully 

 branched or hooked at their tips. In the interior of the recep- 

 tacles, pear-shaped or ovate asci are formed in clusters, attached 

 together at the base, and containing two or more hyaline 

 sporidia. Other forms of fruit have also been observed on 

 the same mycelium. In an exotic genus, Meliola, the fulcra, or 

 appendages, as well as the mycelium, are black, otherwiss it 



* Tulasne, " Selecta Fungorura Carpologia," vol. i. Lcveille, "Organisation, 

 &c., sur I'firysiphe," in "Ann. des Sci. Kat." (1851), vol. xv. p. 109. 



