516 DR LAUDER LINDSAY ON NEW LICHENICOLOUS MICRO-FUNGI. 



(e) Many minute parasitic fungi, belonging especially to the genus Sphceria. 

 if). Certain members of the pseudo-genus (of lichens) Pyrenothea. 

 (g). Granules of coal dust, or other inorganic foreign bodies. 



From all of these the Torula is readily distinguished on microscopical examination, 

 more especially by the presence of its peculiar spore-chains or filaments. There is 

 no complete perithecium; but the basal cellular tissue, from which spring the spore- 

 filaments, and which is generally sub-immersed in the host, is indistinguishable 

 from that which constitutes the envelope or perithecium in many lichens, fungi,* 

 or fungo-lichens, and their spermogonia or pycnidia. The cellular tissue in 

 question is most frequently of an indigo colour, or bluish or bluish-black, though 

 sometimes also it is brownish ; not varying, however, in colour to so great an 

 extent as do the spores. The free surface, which is granular or powdery, consists 

 of spores separated from their filaments, and of the apices of the spore-filaments, 

 which are closely aggregated, just as are the sterigmata or basidia in lichen or 

 fungus-spermogonia, and pycnidia. In the young state, these filaments are 

 simple hyaline tubes, resembling the simple paraphyses of many lichens, broader 

 or thicker at the distal or free end, tapering into a thread-like pedicle at the lower, 

 basal or proximal extremity. Gradually, however, articulations appear, beginning 

 first at the distal end ; and colour is added, the filament increasing in volume. 

 The filaments then resemble the articulated paraphyses of many lichens, e.g., 

 Lecidea lenticularis, Fr. Usually in maturity four or six articulations are formed, 

 and gradually thrown off one after another from the distal end as free spores. 

 Sometimes only one or two articulations are developed. The spore-filaments 

 necessarily vary considerably in length, but less so in breadth. Some filaments 

 appear to be abortive, and maintain throughout the simple or non-articulated, 

 colourless character ; not even increasing in length. These sterile filaments are 

 intermixed with the fertile ones — just as sterile sterigmata — in this case gene- 

 rally elongated and ramose, and exceptionally articulated or pseudo-articulated, 

 frequently accompany the fertile ones in the spermogonia of many lichens f 

 Occasionally there is atrophy of certain articulations, which then assume the 

 character of threads connecting the normal spores. The distal half of the spore- 

 filament is generally coloured, though the colour is sometimes faint or excep- 

 tionally absent. Where colour exists, it is always deepest at the distal or free 

 end — in the terminal articulation. This colour is most frequently bluish (indigo 

 or with a blackish shade) ; but sometimes it consists of various shades of olive 

 or brown. The colour of the spore-filament is that also of the articulations of 

 which it is composed. The colour of the spores is much more variable than their 



* E.g. Dlchana rugosa, Fr. 



f Vide author's " Memoir on Spermogones and Pycnides." Trans. Royal Society of Edinburgh, 

 vol. xxii. plates iv. v. vi. vii. viii. xi. xii. 



