MISS 5. LONGMAN ON THE DRY-ROT OF POTATOES, 129 
3. The colour-phases of mycelium and spores appear to be associated with 
stages in the life-history of the fungus and not, as Smith and Swingle 
suggest, with the nature of the culture-medium. 
4. Sterilization of tubers by heat is not possible since the death-temperature 
of the fungus is higher than that of the potato. | 
In conclusion I desire to express my thanks to Messrs. Sutton for their 
kindness in providing the large quantity of healthy potatoes (“ Abundance ”) 
used in the course of these experiments ; and to Professor Keeble, in whose 
laboratory the work was carried on, for the help and advice which he has 
given me whilst this enquiry was in progress. 
Literature referred to in the Teat. 
(88) JENsEN, J. L.—The propagation and prevention of Smut in Oats and 
Barley. Journ. Roy. Agric. Soc. England, ser. 2, vol. xxiv. Pt. I. 
pp. 397—415. (See also Prillieux, ‘Maladies des Plantes Agricoles,’ 
i. p. 205.) 
(00) LixpAv.—Fungi Imperfecti (Hyphomycetes). Engler & Prantl, Nat. 
Pflanzen-Fam., I Teil, i. Abt.** pp. 415-517, 1900. 
(02) Векхакр, NoEL.—Hev. Gén. de Bot., t. xiv., 1902, pp. 5-25, 58-71, 
101-119, 139-154, 170-183, 269—279. 
C04) Surrg, E. F., & D. B. SwraLE.—The Dry-Rot of Potatoes due to 
Fusarium oxysporum. U.S.A. Dept. of Agric., Bur. Pl. Indust. Bull. 
no. 55, 1904. (With lists of the more important references up to 
1904.) 
(04) Massxz, G.—Some Diseases of the Potato. Journ. R. H.S., Dec. 1904. 
(08) Hearn, F. D.—Seed treatment for the Smuts of Winter-barley. Report 
Agric. Exp. Stat. Univ. Nebraska, Jan, 1908. 
EXPLANATION OF PLATE 10. 
А. Spores of Fusarium Solani, showing aseptate and septate forms, 
B. Spores of the first type, p. 122, containing refractive bodies. 
C. Spores of the second type, Z.c., directly borne upon the mycelium, 
D. Pustules of Dry-rot, x 7; DI, the same, natural size. 
