478 Bacterial Disease of Pisum sativum 



PLATE VII. 



Growth of Ps. seminum during a period of twelve hours, on a film of acid ( 1 per cent, 

 normal HCl) pea agar agar. 



Fig. 1. Oval bodies, 12.20 p.m. 



Fig. 2. 3.10 p.m. Rods developed from the oval bodies. 



Fig. .3. .3.40 p.m. 



Fig. 4. 3.55 p.m. Complete division occurred in groups a and /. 



Fig. 5. 4.25 p.m. Second division beginning in a group, parallel position in / group. 

 Complete division in c group and beginning of parallel position. 



Fig. 6. 5.25 p.m. Third division in a group. Parallel positions in c group after second 

 division. Incomplete division in e group. Grcwth beginning in g. 



Fig. 7. 6.30 p.m. Still incomplete division in e group. Development in g. Parallel 

 growth in d and/ groups. 



Fig. 8. 7.30 p.m. Complete division in e group for the first time, after four sub- 

 divisions. Parallel growth in h group. 



Fig. 9. 9.5 p.m. Division occurring in g group. Parallel growths in a, h, /, d groups. 

 One very long rod in c group. 



Fig. 10. 11.50 p.m. Complete division and beginning of parallel growth in g group. 

 Beading showing in / group. 



Fig. 11. Flagellae of Ps. seminum. 



Fig. 12. Different types of submerged colonies of Ps. seminum grown on different media. 



(a) Submerged colony on acid pea agar. 



(h), {(•), {d). Submerged colonies on alkaline pea agar. 



('')' ( / )• Submerged colonies from green peas on acid pea agar. 



(g) Submerged colony on neutral pea agar. 



Fig. 13. (h) (h) Spreading surface colonies. 



(»') {i) Round surface colonies, on acid pea agar agar, plated after three months' 

 incubation of a piece of the centre of the cotyledon of a dry pea. 



-Fig. 14. Showing different stages of Ps. seminum. Note capsules, oval bodie-s of various 

 shapes, and spores. 



BIBLIOGRAPHY. 



1. Benecke, W. Ban und Leben der Bakterien, 1912. 



2. Beauverie, J. Comptes Rendus, Vol. clvt, May 1913; CLVii, Nov. 1913. 



3. Bboili, J. J., and Schikorra. Ber. d. deut. hot. Gesell. Vol. xxxi, Part 7, 1913. 



4. Cayley, D. M. Proc. Roy. Soc. B. Vol. lxxxvi, 1912. 



5. Chittenden, F. J. Journal Roy. Hart. Soc. Vol. xxxvi, Part 3, 1912. 

 . The Sweet Pea Annual, 1912. 



6. HoLZMULLER, K. Centralhl. fur Bakt. Abt. ii, Bd. xxiii, 1909. 



7. J0HN.SON, J. C. Centralhl. fur Bakt. Abt. Ii, Bd. xxxv, 1912. 



