Xll 
Index. 
Figures. page 
4, 5. Amounts of carbon dioxide absorbed per square metre each two hours by two pinnae 
of coco-nut (lower graph) and spread of edges of pinnae (upper graph) on 
May 25 and May 28, 1918 (McLean) 378 
6, 7. 6. Ditto absorbed per square metre each two hours by three pinnae of coco-nut 
(lower graph) and spread of edges of pinnae (upper graph) on May 21, 1918. 
7. Ditto by two detached pinnae of coco-nut on May 29, 1918 (McLean) . 385 
8, 9. Amounts of carbon dioxide absorbed by a detached abaca leaf on May 18 and 
' May 31, 1898 (McLean) 387 
1. Inoculated sugar-cane plant (Dastur) 393 
2-10. 2. Longitudinal section of an inoculated leaf-bud showing the penetration of hyphae 
in four days. 3. Longitudinal section of a scale leaf. 4 and 5. Hyphae in 
the hairs of a scale leaf. 6-9. Penetration of hairs by the germ-tube from 
sporidia. 10. Hairs from scale leaves (Dastur) 395 
Graphs 1, 2. 1. Maximum and minimum temperature curves on Jan. 6, Feb. 1, and Mar. 1. 
2. Picea canadensis (leaves) (Lewis and Tuttle) 409 
Graphs 3, 4. 3. Populus tremuloides (bark and cortex). 4. Linnaea borealis (leaves) (Lewis 
and Tuttle) 410 
Graph 5. Pyrola rotundifolia (leaves) (Lewis and Tuttle) . . . . . .411 
1. Picea canadensis. Feb. 21. Mesophyll cells showing ‘ laking ’ of the chloroplast. 
Identity of individual chloroplasts completely lost ; nuclei are prominent and 
very granular (Lewis and Tuttle) 413 
2-5. Picea canadensis. 2. Feb. 28. Mesophyll cells after treatment with 1 % osmic 
acid showing vacuoles filled with fats. 3. April 7. Mesophyll cells treated with 
iodine solution. 4. April 10. Mesophyll cells in iodine solution. 5. April 14. 
Mesophyll cells treated with iodine solution (Lewis and Tuttle) . . . 414 
1. Cyclamen neapolitanum. A germinating seed, showing the cotyledon petiole and 
the rudiment of the second cotyledon (Hill) 420 
2, 3. C. neapolitanum. 2. The cotyledonary lamina with the seed have been removed, 
and the second cotyledon is developing. 3. The first cotyledon has been 
unable to free its lamina from the seed-coat, and the second cotyledon has 
developed and expanded its lamina (Hill) . . . . . . .421 
4-7. 4. C. persicum. The petiole of the normal cotyledon with the lamina removed. 
5. C. balearicum. The formation of new laminae from the cotyledonary petiole. 
6. C. persicum. The new lamina has developed a petiole and the lamina has 
been removed. 7. The development of new laminae from the secondary petiole 
(Hill) 422 
8. A seedling of C. persicum from which the top of the tuberous hypocotyl with the 
cotyledon has been removed (Hill) . . . . . . . .423 
9. C. persicum. A first cotyledon cutting more fully developed, showing the cotyledon 
and plumular leaves (Hill) 425 
10-15. C. persicum. 10. A first plumular leaf put in as a cutting Nov. 6, 1918, which 
developed a callus and also roots. 1 1. A seedling in which the second cotyledon 
has been produced on removal of the first cotyledon. 12. One of the flange 
laminae of the second cotyledon in side view. 13. A second cotyledon struck 
as a ‘ cutting’. 14. An adventitious leaf developed from a decapitated seedling 
tuber struck as a cutting. 15. A tuber of a seedling Cyclamen from which the 
upper portion has been removed, showing one fully developed adventitious leaf 
and others as marginal protuberances (Hill) . . . . . . -427 
1. Rudiment of adventitious leaf as seen in a transverse section of the tuber (Boodle) 431 
2-4. 2. Portion of transverse section of tuber, showing procambial trace of young 
adventitious leaf. 3. Transversely cut procambial strand of trace of adven- 
titious leaf. 4. Longitudinal section through a portion of a similar trace 
(Boodle) 433 
5, 6. 5. Longitudinal section of tuber, partly diagrammatic, showing vascular supply of 
adventitious leaf. 6. Portion of trace of adventitious leaf cut longitudinally 
(Boodle) 434 
