400 A CENTURY OF PROGRESS IN THE NATURAL SCIENCES 



Walton, J. (Cont.) 



1931. Contributions to the knowledge of Lower Carboniferous plants. III. Philos. 

 Trans. Roy. Soc. London, B 219:347-379. 



1949a. A petrified example of Alcicornopteris (A. Hallei sp. nov.) from the Lower 

 Carboniferous of Dumbartonshire. Ann. Bot., London, n.s., 13:445-452. 



1949b. CalathospermuTn scoticum, an ovuliferous fructification of Lower Carbonifer- 

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1952. L'^volution des teguments et de la protection du sporange. Ann. Biol. Paris, 

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Warming, E. 



1873. Untersuchungen iiber Pollen bildende Phyllome und Kaulome. Bot. Abh., J. 

 Hanstein, ed., 2(2): 1-90. 



1877. Undersogelser og betranktninger over Cycadeerne. Forhandl. K. Danske 

 Videnskabernes Selsk., pp. 88-144. 



Webber, H. J. 



1901. Spermatogenesis and fecundation of Zamia. Bull. U. S. Dept. Agri., Bur. Plant 

 Industry, 2:1-92. 



Weber, 0., and J. T. Sterzel 



1896. Beitrage zur Kenntnis der Medulloseae. Ber. Naturwiss. Ges. Chemnitz, 13: 

 44-143. 



Wetmore, R. H. 



1943. Leaf-stem relationships in the vascular plants, Torreya, 43:16-28. 



Wettstein, R. 



1911-1935. Handbuch der systematischen Botanik. 2nd ed. (1911), viii + 915 pp.; 3rd 

 ed. (1924), viii + 1018 pp.; 4th ed. (1935), x + 1149 pp. Leipzig u. Wien: 

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1925. Die Bedeutung der sero-diagnostischen Methode fiir die phylogenetisch-syste- 

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 36:438-445. 



White, D. 



1904. The seeds of Aneimites. Smithson. Misc. Colls., 47:322-331. 



WiELAND, G. R. 



1899-1901. A study of some American fossil cycads. Amer. Journ. Sci., ser. 4, 7:219- 



226; 11:423-436. 

 1906, 1916. American fossil cycads. I-II. Publ. Carnegie Inst. Washington. Vol. 34(1), 



viii + 296 pp.; Vol. 34(2), vii + 277 pp. 

 1919. Classification of the Cycadophyta. Amer. Journ. Sci., ser. 4, 47:391-406. 



1934. Fossil cycads, with special reference to Raumeria Reichenbachiana Goeppert 



sp. nov. of the Zwinger of Dresden. Palaeontographica, B 79:85-130. 



1935. The Cerro Cuadrado petrified forest. Publ. Carnegie Inst. Washington, 449: 



i-ix, 1-180. 



Wilde, M. H. 



1944. A new interpretation of coniferous cones. I. Podocarpaceae (Podocarpus) . 



Ann. Bot., n.s., 8:1-41. 



Wilde, M. H., and A. J. Eames 



1948-1952. The ovule and "seed" of Araucaria Bidwillii with discussion of the tax- 

 onomy of the genus. I. Morphology. II. Taxonomy. Ann. Bot, n.s., 12:311- 

 326; 16:27-47. 



