880 LIFE-HISTORY OF PHOMA CITRICARPA, 



2. It develops only on the sunny side of trees, and upon the 

 parts of the fruit exposed to suidight. 



3. Pkoma citricarpa produces two kinds of spores, normal 

 pycnospores, and "x" spores. 



4. Normal pycnospores germinate readily in suitable media: 

 it has not been possible to induce the ''x" spores to germinate. 



5. The details of the formation of the pycnidia, anfl of the 

 pycnospores have been worked out. 



6. Spraying with Bordeaux (6 - 4 - 50; followed up by spray- 

 ings with weaker solutions, controls the disease. 



7. A study of the life-history of the fungus indicates that spray- 

 ing need not commence till the fruit is half grown. 



LITERATURE CITED. 



1. Benson, A. H. — "Black Spot of the Orange." Agric. (iaz. X. S. 



Wales, Vol. \i., Pt.4, p.249 (1895). 



2. UoBB, N. A.— "Black Spot of the Orange." Op. ell.. Vol. viii., Pt.4. 



p. 229 (1897). 



3. Mc Alpine, D.— The Fungus Diseases of Citrus Trees in Austialia (1899). 



4. Saccardo — Sylloge Fungoruni, Vol. xvi., 854. 



5. Cobb, X. A. — Letters on Diseases of Plants. Second Series, p. 72 



(1904). 



6. Wolf. F. A.— ''Egg-Plant Rots" Mycol. Central!).. Vol.4, p. 27S 



(1914). 



7. Van der Bljl. Pail A. — "A study of the "Dry Rot" disease of Maize. 



caused by Diplodia zt<f." Science Bulletin, Xo.7. Dept. of Agri- 

 culture, Union of S. Africa, 



8. Briekley, \V. B.— Kew Bulletin, 1910, Xo.5. 



9. Annals of Botany, xxviii., 1-18, Jan. 1914. 



KXIVLAXATIOX OF PLATES LXXXIV.-XC. 

 Plate Ixxxiv. 

 Fhoma cifric((rpa. 

 Fig. 1. — Pure cultuie in gluco.se-agar. The cidture grows ver^^ rapidly, 

 produces numerous aerial hj'plije, forming a grey-coloured felt, but 

 does not readilj' produce pj'cnidia. 

 Fig.2. — Pure culture growing upon orange-rind-extract agar. The culture 

 grows at a moderate rate, remains dark in colour, produces few 

 aerial hj'plue, and forms pycnidia readily. 



