HYSTERIALES 297 



pinastri, Hypodermella sulcigena and Hypoderma deformans on pines, L. 

 macrosporum on spruce, L. nervisequum on white fir, Hypodermella laricis 

 and L. laricinum on larches, etc. (Tubeuf, 1901; Haack, 1911). The 

 needles of the young plants are infected in the summer by the ascospores, 

 and begin to turn yellow, browning in zones. In the first year, the fungus 

 forms pycnia, in the second and third, when the needles have fallen, 

 hysterothecia. 



In Lophodermium hysterioides on Crataegus Oxyacantha, the mycelium 

 from the germinating spore penetrates the stoma and forms a small 

 sclerotium in the substomatal cavity. This then gradually invades the 

 mesophyll. The pycnia develop under the cuticle and form flat discs 

 of the Leptostroma type. Likhite was unable to effect germination of 

 conidia. About the end of January the apothecia develop, often in the 

 vicinity of the pycnia. In the hysterothecial stroma large multinucleate 

 cells give rise to uni- or binucleate spiral ascogonia, lying in the plane of 

 the hysterothecium. Pores form in the cell walls and nuclear migration is 

 probable, although not observed. Paraphyses develop from spherical 

 mother cells with many small nuclei. In April and May ascogenous 

 hyphae arise from some of the ascogonial cells, while the rest degenerate 

 and develop, without the formation of hooks (Killian and Likhite, 1924; 

 Likhite, 1926). 



Close relatives of the Hysteriaceae form with species of Trentepohlia, 

 crustose lichens, which are common on tree trunks, especially in the 

 tropics, e.g., Graphis scripta. 



