BERNT LYNGE. M.-N. KL 



In Physcia, the gonidia are placed in a stratum under the upper cortex, 

 in Anaptychia they are deeply immersed in the thallus. In some species, e. g. 

 Physcia stellaris, the surface of the stratum is relatively even, in others, 

 e. g. Ph. aipolia and Ph. caesia, it is more uneven, the gonidia being 

 glomerate, and the glomeruli not always continuous. A moistened thallus 

 will then seem marbled, green spots (gonidia) on an uncoloured ground. 

 This is also the case with several Parmeliae, e. g. of the c^ra/a-section. 

 If the thallus is dorsiventral and appressed there are few gonidia if any 

 at the lower part of the medulla. Erect or ascendant laciniae, however, 

 offer an opportunity for assimilation also to the lower side, and gonidia 

 are then frequently found within the lower cortex (if uncoloured). In 

 the apothecia, the gonidia are crowded in the margin, usually also within 

 the* cortex of the receptacle, but wanting or very poorly developed under 

 the hypothecium. In a few species only there is a regular stratum of 

 gonidia under the hypothecium. This must depend on organisatory pecu- 

 liarities of the Physciaceae, for in the Parmeliaceae the hypothecium is seen 

 resting on a stratum of gonidia. There is frequently a dark zone of 

 the cortex around the peduncle; the gonidia are then wanting within 

 that zone. 



The paraphyses are imbedded in a gelatina which in many species is 

 very firm, especially at the epithecium. A drop of potassium hydrate will 

 contribute to their isolation, which in many cases is not easily accomplished. 

 The greater part of the paraphyses is undivided, but in all the Norwegian 

 species there is a varying number of furcate or branched paraphyses in 

 every mature apothecium. The spores are dark, one-septate, only 

 quite exceptionally three-septate, and simple spores were never seen. 

 They are straight or slightly fabiform, broadly or narrowly rounded at the 

 ends; in some species constricted at the septum, in others not. The sep- 

 tum and the cell-wall are more or less incrassate, leaving a cell-room of 

 different form, varying from a narrow fissure across the spore to a 

 large rounded space. In the cell-wall there are two strata: a narrow 

 exterior one of uniform thickness, and an interior one of very variable 

 thickness. The pore is distinct in young spores, but not always in old 

 ones; it is evidently frequently filled up with an opaque substance. 



On the whole, the Physciaceae are lowland species in our country. There 

 is only one real mountain species (Ph. muscigena) which is frequent on the 

 mountains and rare on the lowlands of Southern Norway, and frequent in all 

 elevations in Northern Norway. On the mountains we also find Ph. tribacia, 

 Ph. lithotea, and Ph. caesia, but with the exception of a few alpine forms 



