486 OC'CURBEKCE OP OIL DUCTS IN (JliKTAIN EUCALYPT.S ASU ANGOPUOHA.S. . 



Fig. 3. 



E. haematoxylon J. 11. M. Transverse section oi' stem showing- nine ducts, 

 five of wbich are abnoiiual. There are also four oil glands present in the cortex. 

 Fig. 4. 

 E. pyrophora Benth. Transverse leaf section with two ducts almost com- 

 pletely closed by a dark residue. There are also several phloem carities as this 

 material was dry when examined. The palisade tissue extends right across the 

 leaf. 

 Fig. 5. 

 E. latifolia F. v. M. Transverse leaf section with three ducts, one of which 

 retains a dark residue. Small phloem cavities are seen also in this section, 

 which was made from dried material. The palisade extends right across the 

 leaf, and stomata are developed on either side. 

 Fig. 6. 

 E. Foelsckeana F. v. M. Transverse leaf section with only one duct, the 

 number usually found in the dried material examined. The numerous large 

 cavities in this section are due to the disintegration of the intraxylary phloem, 

 apparently caused by the pressing during preparation as a herbarium specimen 

 and subsequent softening of the leaf for sectioning. The palisade tissues extend 

 right across the lamina. 



Plate slvi. 

 Fig. 1. X 30; Figs. 2, 4 and 5. x 50; Fig. 3. x Go; Fig. (J. x 20; Fig. 7. x 155. 



Fig-1. 



E. corymbosa Sm. Transverse section of petiole showing two ducts. These 

 are usually larger in diameter than those in the leaf. 

 Fig. 2. 



E. ficifolia F. v. M. Tiansvcrse leaf section with two ducts. The contents 

 are usually colourless or very ])ale yellow, minutely granular, and soluble in 90 

 per cent, alcohol. Tiie palisade is developed towards the upper surface only, 

 and stomata are found on the lower epidermis. 

 Fig. 3. 



E. traehyphloia F. v. M. Transverse leaf section with two ducts, the con- 

 tents being usually light yellow and soluble in 95 per cent, alcohol. The 

 palisade shows greater development towards the upi>er surface, and stomata 

 are found on tlic lower side only. 

 Fig. 4. 



E. intermedia R. T. P.. Transverse leaf sectiim with two comparatively 

 large ducts, containing a small amount of residue; this section being obtained 

 from dried material. The palisade mesophyll consists of one or two rows of 

 cells towards the upper epidennis. 

 Fig. 5. 



E. corymbosa Sin. Median section parallel to the leaf surface with two 

 oil duets in the mid-rib. On cither side are a number of oil glands distributed 

 in the mesophyll of the leaf. 

 Fig. 6. 



E. corymbosa Sm. I\l('<]ian longitudinal section through a leaf bud sliowing 

 two leaf ducts, and on the right are evidences of two stem ducts. There is no 

 direct connection between these two systems of ducts. 

 Fig. 7. 



E. corymbosa Sm. Portion of one of the leaves in the preceding figure 

 nn<ler a greater magnification, showing the "duct" composed of a row of small 

 elongated cavities, coriesponding in size and shape to the oil gland seen above. 

 By the breaking <lown of the transverse walls the passage becomes continuous. 



