ACKNOWLEDGMENTS 



For permission to reproduce and to base diagrams on illustrations in the 



books mentioned we are indebted to the following: — 



The Editors, Annals of Botany; The Cambridge University Press 

 for Rendle, Classification of Flowering Plants and Arber, Water 

 Plants; Chronica Botanica, Waltham, Mass. for Erdtman, An Intro- 

 duction to Pollen Analysis, Erdtman, Pollen Morphology and Johansen, 

 Plant Embryology; Messrs. Paul Le Chevalier for Bois, Les Plantes 

 Alimentaires; McGraw Hill Book Company Inc. for Maheshwari, 

 An Introduction to the Embryology of Angiosperms; Messrs. L. Reeve 

 and Co. Ltd. for Ridley, The Dispersal of Plants and Messrs. Rout- 

 ledge and Kegan Paul, Ltd. for Lubbock, A Contribution to our 

 Knowledge of Seedlings. 



The following works have also been consulted to which we wish to 

 make due acknowledgment: — 



Eichler, Bliitendiagramme ; Engler and Prantl, Die Naturlichen 

 Pflanzenfamilien; Goebel, Organographie der Pflanzen; Kerner and 

 Oliver, Natural History of Plants; Knuth, Handbuch der Bliiten- 

 biologie; Le Maout and Decaisne, General System of Botany; Lotsy, 

 Vortrdge uber botanische Stammesgeschichte ; Schnarf, Embryologie der 

 Angiospermen; \^an Tieghem, Traite de Botanique; Troll, Verglei- 

 chende Morphologic der hoherer Pflanzen; Velenovsky, Morphologic 

 der Pflanzen and Wettstein, Handbuch der systematischen Botanik. 



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