228 Transactions British Mycological Society. 



complete until spring. Leaves placed in muslin bags on the 

 surface of the soil decomposed completely after a few weeks 

 without leaving any traces. 



The perfect stage of the fungus obtained by Killian is the 

 same as that described above but he calls it Plowrightia Trifolii. 

 Dothidella Spegazzini (1880) has priority over Plowrightia 

 Saccardo (1883) (v. Theissen and Sydow, p. 309) and the subject 

 of our investigations must therefore be known as Dothidella 

 Trifolii. 



(I 

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REFERENCES. 

 Bayliss-Elliott, J. S. and Stansfield, O. P. Gardener's Chronicle, 



ser. 3, Lxxiii, p. 221 (1923). 

 Blackman, V. H. and Welsford, E. J. The Development of the Peri- 



thecium of Poly stigma rubriim DC. Ann. Bot. xxvi, p. 761 (1912). 

 Studies in the Physiology of Parasitism. II. Infection by Botrytis 



cinerea. Ann. Bot. xxx, p. 389 (1916). 

 Claussen, p. Zur Entwicklungsgeschichte der Ascorayceten, Pyronema 



confluens. Zeitschr. f. Bot. iv, p. 35, Taf. 4 (1912). 

 Clevenger, J. F. Journ. Mycol. xi, p. 160 (1905). 

 Cooke, M. C. Grevillea, xiii, p. 63 (1885). 

 Corda, A. J. C. Pilze in Sturm, J. Deutschlands Flora, iii, Hft. 10, 



p. 17, tab. 9 (1830). 



Icones Fungorum, iii, p. 10, Tab. II, fig. 25 (1839). 



Fries, E. Syst. Mycol. 11, p. 435 (1823). 



. Summa Veg. Scand. p. 387 (1846). 



Fuckel, L. Symb. Mycol. p. 218 (1869). 

 . Kunze, G. and Schmidt, J. K. Mykol. Hefte, i, p. 13 (1817). 

 . Persoon, C. H. Syn. Fung. p. 30 (1801). 

 Theissen, H. and Sydow, H. Die Dothideales. Ann. Mycol. xiii, 



p. 576 {1915)- 



EXPLANATION OF PLATE. 



Fig. I. T. S. clover leaf showing mature conidial stroma with conidiophores 



producing conidia. x 325, 

 Fig. 2. Surface of leaf showing early stages in stromata development with 



connecting hyphal strands. No conidiophores are yet developed, x 200. 

 Fig. 3. Stromata at a later stage. Conidiophores beginning to appear, x 200. 

 Fig. 4. Hymenial surface of pycnidium. x 750. 

 Fig. 5. Pycnidial stroma showing disintegration of pseudo-parenchymatous 



tissue. X 325. 

 Fig. 6. Asci and ascospores crushed from a perithecium. x 325. 

 Fig. 7. Perithecial cavity showing asci associated in pairs and large fusion 



nucleus, a, paired nuclei, x 325. 

 Fig. 8. Later stage. L, S. stroma showing pseudo-parenchymatous tissue 



tending to radiate from a central point, and cells becoming less polygonal. 



X325- 

 Fig. 9. a. Ascogenous hypha showing paired nuclei and ascus containing large 



fusion nucleus arising from a penultimate cell. b. Young ascogenous hypha. 



