128 Sprcitt . — Root Tubercles of Aimes and Elaeagnus. 
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DESCRIPTION OF PLATES XIII AND XIV. 
Illustrating Miss Spratt’s paper on the Root Tubercles of Alnus and Elaeagnus. 
In Figs. 3, 4, 5, 7, 13, and 16, x — xylem ; ph — phloem; p — pericycle; e = endodermis; 
c — cork ; b = bacteroidal cells ; f = reserve food material ; m = meristematic zone. 
In Figs. 6, 8, 14, 15, b — bacillus form; c = coccus form; d = coccus form dividing; 
z = zoogloea ; n — nucleus. 
Fig. 1. Root tubercles of Alnus incana . Natural size. 
Fig. 2. Root tubercles of Elaeagnus edulis. Natural size. 
Fig. 3. Transverse section of root tubercle of Alnus. x 70. 
Fig. 4. Transverse section of stele at tip of tubercle of Alnus. x 70. s = parenchyma. 
Fig. 5. Transverse section of stele near base of tubercle of Alnus. x 70. 
Fig. 6. Cortical cells of Alnus incana. x 325. g = proteid globules. 
Fig. 7. Longitudinal section of tubercle of Alnus. x 37. 
Fig. 8. Cortical cells of Elaeagnus , showing bacillus and coccus forms, zoogloea, and host 
nucleii. x 325. 
Fig. 9. Pseudomonas radicicola isolated, rod-shaped form, x 1,180. 
Fig. 10. Pseudomonas radicicola isolated, rod-shaped form changing to coccus. X 1,180. 
Fig. 11. Pseudomonas radicicola isolated, coccus form, x 1,180. 
Fig. 12. Pseudomonas radicicola isolated, coccus form changing to bacillus, x 1,180. 
Fig. 13. Transverse section of tubercle of Elaeagnus. x 7 °* — secondary xylem. 
Fig. 14. Cortical cells of Elaeagnus , showing coccus forms changing to bacillus, x 325. 
Fig. 15. Cortical cells from basal region of Elaeagnus tubercle showing Bacteria, and reserve 
food material as oil at 0 . x 325. 
Fig. 16. Longitudinal section of root tubercle of Elaeagnus. x 37. 
