RELATION TO ENVIRONMENT 529 



'92. 22. Riley, C. V. The Yucca Moth and Yucca Pollination. 3d Annual 



Report Missouri Hot. Garden. St. Louis, 1892. 

 23. Robertson, C. Numerous papers on the Pollination of American 



flowers, in the Botanical Gazette. 



'98. 24. Schimper, A. F. W. Pflanzengeographie. Jena, 1898. (This im- 

 portant work contains extensive bibliography.) 

 '89-'90. 25. Scott-Elliot, G. F. Ornithophilous Flowers in South Africa. 



Ann. of Bot., IV. 1889-90. 

 '90-91. 26. Fertilization of South African and Madagascar Plants. Ann. 



of Bot., V. 1890-91. 



'92. 27. Wallace, A. R. Island Life. 2d edition, London, 1892. 

 '97. 28. Warming, E. W. (Ekologische Pflanzengeographie. 1897. 

 '89. 29. Wilson, W. P. The Production of Aerating Organs on the Roots of 



Swamp and Other Plants. Proc. Acad. Nat. Soc., Philadelphia. 



1889. 

 '01. 30. Wilson, W. M. The Compound and Mixed Nests of American Ants. 



American Naturalist, XXXV. Aug. -Oct., 1901. 



