SPERMOGONIA 201 



paraphyses, and also in Steganosporium cellulosum (Melanconieae). These 

 observations have been confirmed by Allescher^ in his recent work on Fungi 

 Imperfecti. Keiszler^ has described a PhomaASk^ pycnidium parasitic on 

 the leprose thallus of Haematomma elatinum. It contains short slender 

 sporophores and, mixed with these, long branched sterile hyphae which 

 reach to the ostiole and evidently function as paraphyses, though Keiszler 

 suggests that they may be a second form of sporophore that has become 

 sterile. On account of their presence he placed the fungus in a new genus 

 Lichenophoma. 



E. Spermatia or Pycnidiospores 



a. Origin and Form of Spermatia. Lichen spermatia arise at the 

 tips of the sterigmata either through simple abstriction or by budding. In 

 the former case — as in the Squamaria type — a delicate cross-wall is formed 

 by which the spermatium is separated off. When they arise by budding, 

 there is first a small clavate sac-like swelling of the end of the short process or 

 sterigma which gradually grows out into a spermatium on a very narrow base. 

 This latter formation occurs in the Sticta, Physcia and Endocarpon types. 



Nylander^ has distinguished the following forms of spermatia: 



1. Ob-clavate, the broad end attached to the sterigma as in Usneae, 

 Cetraria glauca and C. jtmiperina. 



2. Acicular and minute but slightly swollen at each end, somewhat 

 dumb-bell like, in Cetraria nivalis, C. cucullata, A lectoria, Evernia and some 

 Parmeliae, frequently borne on "arthrosterigmata." 



3. Acicular, cylindrical and straight, the most common form ; these occur 

 m most of the Lecanorae, Cladoniae, Lecideae, Graphideae, Pyrenocarpeae 

 and occasionally they are budded off from arthrosterigmata. 



4. Acicular, cylindrical, bent; sometimes these are very long, measuring 

 up to 40^1; they are found in various Lecideae, Lecanorae, Graphideae, 

 Pyrenocarpeae, and also in Roccella, Pilophoncs and species of Stereocaidon. 



5. Ellipsoid or oblong and generally very minute; they are borne on 

 simple sterigmata and are characteristic of the genera Calicium, Chaenotheca, 

 Lickina,Ephebe,oi the. small genus Glypholecia and of a few species ol Lecanora 

 and Lecidea. 



In many instances there is more or less variation of form and of size in 

 the species or even in the individual. There are no spherical spermatia. 



b. Size and Structure. The shortest spermatia in any of our British 

 lichens are those of Lichina pygmaea which are about i'4/a in length and 

 the longest .are those of Lecanora crassa which measure up to 39 ^. In width 

 they vary from about 0'5 /u. to 2 /x. The mature spermogonium is filled with 



^ AUescher 1901-3. ^ Keiszler i^ir. ' Nylander 1858, p. 37. 



