252 BIBLIOGRAPHY 



Sex." 1889. Revised Edition, 1901. [A discussion 

 of sexual selection, the reproductive factor in evolution, 

 the physiological interpretation of sex, and so forth. 

 The general thesis is that maleness and femaleness are 

 expressions of alternatives in the regulated rhythm of 

 metabolism. ] 



GEOOS, K. "The Play of Animals." Translation, 1900. [A 

 very suggestive book, a proof of the biological importance 

 of play, with an important contribution to the theory of 

 sexual selection.] 



GULICK, J. T. "Evolution, Racial and Habitudinal. " 1905. 

 [Elaborate discussion of isolation as a factor in evolution.] 



***HAECKEL, ERNST. "Generelle Morphologie." 2 vols.,1866. 

 [A classic work, to be placed beside Spencer's "Principles 

 of Biology. " It is now out of print, but part of it has 

 been recently re-issued.] 



"Natural History of Creation." English translation, 



1870. [A picturesque book that has passed through 

 many editions. The early chapters give a vivid account 

 of the rise of the evolution theory. The statement of 

 "the evidences" had a deserved success in vindicating 

 the validity of the evolution formula.] 



*HEADLEY, F. "W. "Life and Evolution." 1906. [Pictur- 

 esque concrete illustrations of the problems of evolution,] 

 See alto " Problems of Evolution. " 1900. 



BUTTON, F. "W. "Darwinism and Lamarckism." 1899. 



HUXLEY, T. H. Article "Evolution" in "Encyclopaedia 

 Britannica," 9th Edition. 



** "American Addresses." (1877). 



JINKINSON, J. W. "Experimental Embryology." 1909. [A 

 very able treatise on the external and internal factors in 

 development. With a valuable discussion of Vitalism 

 and Driesch's contributions thereto.] 



**JOHANNSEN, W. " Ueber Erblichkeit in Populationen und 

 in reinen Linien." 1903. [Important experiments on 

 beans, barley, etc.; notably on the isolation of "pure 

 lines."] See also "Die Elemente der exakten Erblich- 

 keitslehre." 1909. 



JORDAN, D. S., and KELLOGG, V. L. "Evolution and Animal 

 Life." 1907. [Very interesting concrete studies of 

 evolution problems.] 



XBLLOGG, V. L. "Darwinism To-day." 1907. [A remark- 

 able book, with the frankest and friendliest reconsidera- 

 tion of Darwinism, in the light of post-Darwinian progress, 



