240 ASCOMYCETES. 



The mycelium lives intercellular, and produces the same 

 effects on the cells of the fir-needles as those of Loph. macro- 

 sporum on the spruce. The mycelial hyphae penetrate into the 

 epidermal cells and form a cushion, which bursts the epidermis 

 and gives rise to numerous straight conidiophores, with very 

 small, oval, unicellular conidia. The apothecia are developed 

 while the needles are on the tree or after they have fallen ; 

 they form shining black stripes on the middle nerve of the 

 lower surface of the needle (Fig. 124). The thread-like spores 

 have a mucilaginous coat, and are ejaculated from club-shaped 

 asci (Fig. 126). Pycnidia (spermogonia) are often produced 

 before the apothecia as long wavy bands on the middle nerve 

 of the upper surface of the needle (Fig. 125). 



L. juniperinum (Fries.) (Britain and U.S. America). A 

 common species on dead needles of Juniper communis, also on 

 needles on the branch ; I have, however, never seen it in such 

 mass as to believe it to be a dangerous parasite. 



L. gilvum Rostrup^ attacks and kills living needles of the 

 Austrian black pine. 



L. laricinum Duby. The pycnidia and apothecia of this 

 fungus are common on dead needles of larch, but parasitism has 

 not been proved. 



L. abietis Eostr. A species found by Eostrup on needles of 

 spruce, causing yellow spots and then large black points (Fig. 

 121, 2). 



DISCOMYCETES. 



The Discomycetes have an apothecium of varying shape, but 

 always more saucer-like than spherical. The ascocarp, at first 

 a closed structure, opens sooner or later and exposes the 

 hymenium. The apothecium is composed of two distinct portions 

 of mycelium. The essential part, often called the hymenial 

 layer, consists of hyphae which give rise to the asci. The 

 remaining portion of the ascocarp forms a support or envelope 

 for the hymenium; it consists of a pseudoparenchyma, and may 

 be differentiated into a sub-hymenial layer or hypothecium with 

 its hyphae interwoven with those of the hymenium, and a 

 lateral portion or excipulum usually more or less cup-shaped. 



' Rostrup, Fortsatte Undersoegelser, 1883. 



