2g2 Transactions British Mycological Society. 



B. campesiris to B. oleracea invariably gave " subinfections " as 

 the result. 



3. "Biologic forms" on Polygonum aviculare, Trifolium 

 pratense and Pisum sativum were indicated. 



4. " Subinfections " on varieties of B. oleracea were observed 

 in the field and found to exist over the winter and in some cases 

 grow into full infections. 



5. Inoculations were undertaken in the laboratory and were 

 successful both on uninjured leaves and on the internal tissues 

 of stems; these latter were carried as far as the fourth gen- 

 eration. 



6. Inoculations with conidia from "subinfections "were carried 

 out and the conidia shown to be viable. 



7. It is suggested that the most probable method of over- 

 wintering of the "biologic form" of Erysiphe Polygoni on the 

 cultivated Brassicae is by means of " subinfections " on varieties 

 of B. oleracea aided by persistent mycelium on varieties of 

 B. campestris. 



BIBLIOGRAPHY. 



Smith, Grant. — The Haustoria of the Erysipheae. (Bot. 



Gaz. Vol. 29, p. 153, 1900.) 

 Neger, F. W. — Beitrage zu Biologic der Erysipheen. 



(Flora, xc. 221-272, 1902.) 



(3) Marchal, E. — De la Specialisation du parasitisme chez 



Y Erysiphe graminis. (Comptes Rendus, cxxxv. pp. 210- 

 212, 1902.) 



(4) Salmon, E. S. — On Specialisation of Parasitism in the 



Erysiphaceae. (Beitr. z. Botan. Centralbl. xiv. pp. 261- 

 315, 1903.) 

 (5)^ — Recent researches on the Specialisation of Parasitism 

 in the Erysiphaceae. (New Phyt. Vol. 3, No. 5, 1904.) 



(6) — On Erysiphe graminis DC. and its Adaptive Parasitism 

 within the genus Bromus. (Ann. Mycolog. Vol. 11. 

 Nos. 3, 4, 1904.) 



(7) — Cultural experiments with the Barley Mildew 

 Erysiphe graminis DC. (Ann. Mycolog. Vol. 11. 1904.) 

 — Cultural experiments with "Biologic Forms" of the 

 Erysiphaceae. (Phil. Trans. Series B, Vol. 197, pp. 107- 

 122, 1904.) 



(9) — Further cultural experiments with "Biologic Forms" 

 of the Erysiphaceae. (Ann. of Botany, Vol. xix. No, 



73, 1904-) 

 ;io) — On Endophytic Adaptation shown by Erysiphe 

 graminis DC. imder cultural conditions. (Phil. Trans. 

 Series B, Vol. 198, pp. 87-97, 1905.) 



