CONTRIBUTIONS FROM THE WISLEY LABORATORY. 387 



Figure 104. — a-e. Stages in the formation of the cell-ball of Verticillium 

 (X 750). 



A. Lateral branch with special end-cell. 



B. Showing the bending over of the end-cell. 



c. Showing branch-cell developed from one of the investing hyphal cells. 



D. Special-cell almost enclosed. 



E. Cell-ball complete (diam. =:19m.), one special cell enclosed. 



F. Cell-ball (diam. 28m.) with more than one special-cell enclosed. 



G. Cell-ball of Stysanus. 



H. Cell-ball of Stysanus (dimensions 34.5m. X 45m.). 



I. Cell-ball of Stysanus. 



J. Cell-ball found associated with another Hyphomycete (diam. = 42m.) 

 (X 750). 



K-o. Stages in the development of a cell-ball not invested with hyphal cells 

 (X 750). 



K, L. Formation of special cells at the end of a short lateral branch. 

 M. Showing the arching-over of the end-cells. 

 N. A later stage. 



o. Cell-ball complete (length=31m.) 



Figure 105. — Globular bodies in cell of potato fixed in Flemming's solution 

 (stained with osmic acid). 



Figure 106. — Globular bodies in cells of potato. Stained with Triple stain 

 (X 2200). 



BIBLIOGRAPHY. 



1. Anon. " English Potato Scab." Jour. Bd. Agr., XV., No. 1, p. 509 (Oct. 



1908). 



2. " Wart Disease (Black Scab) of Potatoes." Ibid. No. 9, 



p. 671 (Dec. 1908). [Issued as Leaflet No. 105.] 



" Varieties of Scab in Potatoes." Ibid. No. 10, p. 749 



(January, 1909). 



4. " Notes on Insect, Fungus, and other Pests." Ibid. XVI., 



No. 18, p. 642 (Nov. 1909). 



"Results of Experiments as to Wart Disease." Ibid. 



No. 9, p. 762 (Dec. 1909). 

 ■ — ■ — ■ Proc. under Dest. Insects and Pests Acts, 1909-1910. 



Ann. Re'port Intelligence Div. Bd. Agr. and Fish., 1911. 



" American Gooseberry Mildew and otlier Destructive 



Pests." Jour. Bd. Agr., XVII., No. 12, p. 992 (March 1911). 



" Wart Diseases in Potatoes " (Memorandum on Wart 



Disease in Potatoes (No. 2), issued by the Board of Agriculture and 

 Fisheries). Ibid. XVIIL, No. 1, p. 42 (April, 1911). 

 o(lia"^9. M. J. Berkeley. " Observations Botanical and Physiological on the 

 Potato Murrain." Jour. Roy. Hort. Soc., I., p. 9 (1846). 



9. — '■ — " On a Form of Scab in Potatoes." Jour. Roy. Hort. 



Soc, III., p. 37 (1848). 



1. and C. E. Broome, "Notices of British Fungi." 



Ann. Mag. Nat. Hist., V. (ser. 2), p. 464 (1850). 



2. A. W. BoRTHWiCK. "Warty Disea^se of Potato." A''otes R.B.G., Edin., 

 No. XVIII., p. 115 (1907). 



5. J. Brunohorst. " Ueber eine verbreitete Krankheit der Kartoffelknollen." 



Bergens Muse\ini^ Aarsheretning (1886), p. 219. 

 \\. W. Carruthers. Jour. Roy. Agric. Soc, ^Eng., LXIIL, p. 292 (1902). 



). Jour. Roy. Agric Soc, Eng., LXIV., p. 305 (1903). 



>..,M. C. Cooke. " Potato tumour." Jour. Roy. Hort. Soc, XXVII. , p. 815, 

 cxliv. (Aug. 5, 1902) ; " Outgrowths on Potato Tubers," p. cxcviii. 

 (Nov. 4, 1902). 



c c 2 



