226 
BROWN. 
Plate XVI. 
Fig. 14. Root of Cissus containing cells of Rafflesia manillana. In the 
upper and lower parts of the figure are sections of xylem rays 
between which there is a medullary ray. The black spots are 
medullary ray cells with densely staining contents. The cells of 
Rafflesia are seen as a row running transversely across the 
center of the figure. They have deep-gray contents and 
prominent nuclei. X 155 
15. Strand of tissue of Rafflesia manillana in xylem of Cissus. The 
cells of Rafflesia can be distinguished by their deep-gray color 
and prominent nuclei. X 155 
16. Large mass of tissues of Rafflesia manillana in central cylinder of 
Cissus root. X 115 
Plate XVII. 
Fig. 17. Embryonic shoot of Rafflesia manillana in root of Cissus. X 155 
18. Older shoot of Rafflesia manillana. Tissues still undifferentiated. 
X 60 
Plate XVIII. 
Fig. 19. Shoot of Rafflesia manillana at the stage when the growing point 
and vascular bundles are being differentiated. The vascular 
bundles show as dark streaks in the light colored tissue of the 
parasite. X 8.5 
20. Enlarged view of apex of shoot of Rafflesia manillana shown in 
figure 19. The dark tissue at the top of the figure is the bark 
of the host. The layer, a few cells in thickness, which is just 
below this, is the cap which is formed over the growing point of 
Rafflesia. X 100 
Plate XIX. 
Fig. 21. Cross section of Cissus root containing a young bud of Rafflesia 
manillana. The cap over the apex of Rafflesia shows as a dark 
streak under the bark of the host. X 10 
22. Longitudinal section of Cissus root containing older bud of 
Rafflesia manillana. X 7.5 
Plate XX. 
Fig. 23. Cross section of parenchymatous tissue of Rafflesia manillana 
showing irregular division of cells. X 100 
24. Cross section of young vascular bundle of Rafflesia manillana. 
X 100 
Plate XXL 
Fig. 25. Scar left on root of Cissus after the disappearance of the flower 
of Rafflesia manillana. X 1-3 
26. Scar left on root of Cissus after the disappearance of the flower 
of Rafflesia manillana. X 1-3 
27. Cross section through a scar on root of Cissus. X 1.3 
28. Longitudinal section through a scar on root of Cissus. Xl.3 
