8o MICROSCOPICAL RESEARCH 



PLATE V. 



STEM STRUCTURE. 



Fig. 15. Transverse section. Stem of Lime Tree, 'Tilia europoea' 

 x40dia. Fixed in 92% Alcohol. Stained with Borax 

 Carmine and Malachite Green. 1. Cortical tissue. 2. Primary 

 medullary ray. 3. bast (phloem). 4. Cambium-ring. 

 5. Xylem elements, of about three years' growth. 6. Central 

 axis of pith. 7. Medullary sheath containing protoxylem 

 elements. 



Fig. 16. Tangential longitudinal section. Stem of Lime Tree. ' Tilia 

 europoea' x 25dia. The line of cut passing through the ' bast 

 area.' Cut ^/uooin- Stained Hssmatoxylin and Safranin. 

 1. Ground tissue (medullary ray). 2. Bast fibres. 



Fig. 17. Tangential longitudinal section. Stem of Lime Tree. 'Tilia 

 europoea ' x 50 dia. The line of cut passing through xylem 

 elements. Stained with Hsematoxylin and Safranin. 

 1. Connective tissue. 2. Pitted vessels. 3. Medullary ray. 



Fig. 18. Transverse section. Stem of Dracaena. ' Cordyline rubra ' 

 X 50 dia. Fixed in 92% Alcohol. Stained Borax Carmine 

 and Malachite Green. 1. Cortical tissue. 2. Cambiform 

 zone in which new bundles are being developed. 3. Secondary 

 vascular bundles in various stages of development. 4. Primary 

 vascular bundles. 



