THOMAS: INFECTION OF APIUM GRAVEOLENS 27 
is unable to develop on a living host as nearly related to celery as is 
parsley. 
The comparatively narrow specialization of the Septoria on 
celery suggests a promising outlook for experiments in breeding 
for resistance. More intensive work in this direction is needed. 
This work was done in the laboratory of Professor R. A. 
Harper and acknowledgment is herewith made to him for numerous 
helpful criticisms and suggestions. 
DEPARTMENT OF BOTANY 
COLUMBIA UNIVERSITY 
LITERATURE CITED 
Beach, W. S. Biologic specialization in the genus Septoria. 
Am. Jour. Bot. 6: 1-33. I919 
. Blackman, V. H., & Welsford, E. J. Studies in the physiology of 
parasitism. II. Infection by Botrytis cinerea. Ann. Bot. 30: 
389-398. fl. ro + f. 2, 2. 1916. 
i I funghi parasitti della piante coltivate 
ed utili. Fasc. 6: No. 144. 1890. [Original not seen]. 
Chester, F. D. Notes on three new or noteworthy diseases of 
plants. Bull. Torrey Club 18: 371-374. 1891. 
Clinton, G. P. Report of the Botanist. Conn. Agr. Exp. Sta. 
Ann. Rept. 1905: 263-330. pl. 13-25. 1906. 
. Comes, O. Connection between acidity of cell sap and rust resis- 
tance in wheat. [Review of original]. Bull. Agr. Int. and PI. 
Dis. 4: 1117-9. 1913. 
7. Cooke, M. C. Fungoid pests of cultivated plants. London. 
_ 
. 
bo 
yf & 
Ss 
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F 
ane 
ge 
eo: 
<j 
x 
> s 
tt 
On 
8. Coons, H. H., & Levin, E. Septoria leaf spot disease of celery or 
celery blight. Mich. Agr. Exp. Sta. Spec. Bull. 77: 1-8. f. 1-9. 
Ig16. 
Dorogin, G. N. Melanose of celery. Mat. Miko. i Fitopatol. 
Ross. 1: 57-76. f. 1-9. 1915. 
10. Duggar, B. M., & Bailey, L. H. Notes on celery. New York 
(Cornell) Agr. Exp. Sta. Bull. 132: 206-215. f. 51-53. 1897- 
1oa. Ensign, M. R. Venation and senescence of polyembryonic 
citrus plants. _Amer. Jour. Bot. 6: 311-329. f. 1-6. 1919. 
11. Freeman, E. M. The seed fungus of Lolium temulentum L., the 
darnel. Phil. Trans. Roy. Soc. Lond. 196B: 1-27. pl. 1-3. 1903+ 
12. Fromme, F. D. The culture of cereal rusts in the Senne: 
Bull. Torrey Club 40: 501-521. 1913. 
° 
