DR LAUDER LINDSAY ON NEW LICHENICOLOUS MICRO-FUNGI. 551 



(a) Ben Lawers. Intermixed with the pycnidia of the Abrothallus, and 

 externally indistinguishable therefrom, is a minute papillseform parasite, which 

 consists of an envelope of dark-brown, hexagonal, cellular tissue, enclosing- 

 myriads of dark-brown spherical spores, which are frequently irregular or jagged 

 in outline, like blood-corpuscles in a condition of shrivelling from exosmosis. 



(b) Var. Welivitzschii,Tu\.; Amulree Road, Dunkeld. Black perithecia— exter- 

 nally resembling pycnidia, with which they are associated — contain nothing 

 but spherical oil globules, or corpuscles closely resembling them. 



(c) Craigie Hill, Perth As in (a) and (b), intermixed with pycnidia, and like 

 them papillseform or punctiform. They contain — 



1. Largish, spherical corpuscles, with pale brownish-yellow subgranular proto- 

 plasm, resembling the sporidia of certain lichens, e.g. some forms of Lecanora 

 cinerea. Sometimes the protoplasm becomes distinctly circumscribed and 

 separated from the cell-wall by a varying hyaline interspace. This protoplasm 

 gradually acquires a nuclear character and a central position, and then divides 

 into two or four (sometimes three) equal subspherical segments, after the manner 

 of some of the larger forms of gonidia. In age, both cell-wall and outline of 

 nucleus, or its segments, become irregular, as if from shrivelling. 



2. Corpuscles resembling shrivelled sporidia ; most irregular in form, colour- 

 less, generally with double contour, and containing one or more largish, distinct 

 subspherical nuclei, and frequently also fine granular protoplasm. These cor- 

 puscles are often found attached to each other in groups of two or more. 



3. Most irregular, ribbon-like tubules, marked by subspherical nuclei, which 

 are sometimes of an iodine colour. In some cases these would appear to be mere 

 chains of degenerate sporidia. Sometimes only two or three constitute the 

 pseudo-tubule, whose septa (the walls of the sporidia) have disappeared. But 

 at other times the outline of the sporidia remains ; there is a pedicle formed by 

 the base of the shrivelled ascus ; the nuclei are polar and distinct, sometimes 

 yellowish ; or they are connected by a central canal, as in the sporidia of Physeia 

 parietina. 



A solitary black conceptacle, externally resembling an apothecium of the 

 Abrothallus, picked off the bluish, curled squamules of the host {Parmelia saxa- 

 tilis), consists of an envelope of dark-brown, honeycomb-like cellular tissue ; 

 rootlets being sent downwards into the tissues of the thallus of the Parmelia, 

 penetrating through its cortical and gonidic layers to the medullary tissue. It 

 contains — (1.) A parenchymaof colourless hexagonal cells, associated with mycelioid 

 tubes — also hyaline, but short and thickish, and intermixed with much oily 

 matter in the form of globules ; (2.) Largish, spherical, colourless, sporoid 

 corpuscles, full of a nucleiform, cellular, or granular protoplasm. 



On one of the true apothecia of A. Smithii, from Craigie, I found a large, dark- 

 brown, 3-septate sporidium, with bulgings opposite the loculi. Its size and form 



