LITERATURE CITED. 



CLAWSON, A. B. 



1905. Some results of a study of correlation in the crayfish. Seventh Report Mich. 



A cad. Sci., pp. 103-108. 1905. 

 DAVENPORT, C. B. 

 1903. Quantitative studies on the evolution of Pecten. III. Comparison of Pecten 



opercularis from three localities in the British Isles. Proc. Amer. Acad. 



Arts and Sci., vol. xxxix, pp. 123-159, 1903. 

 DRIBSCH, H. 



1901. Die organischen Regulationen. Vorbereitungen zu einer Theorie des Lebens. 



Leipzig (Engelmann), 1901, 8, pp. xv + 228. 



DUNCKER, G. 



1900. On variation in the rostrum of Palaemonetes vulgaris Herbst. Amer. Nat., 



vol. xxxiv, pp. 621-633. 1900. 



1903. Ueber Asymmetrie bei " Gelasimus pugilator " Latr. Biometrika, vol. n, pp. 



307-320. 1903. 

 FAWCETT, C. D. 



1902. A second study of the variation and correlation of the human skull, with 



special reference to the Naqada crania. Biometrika, vol. i, pp. 408-467, 

 pis. iv-x. 1902. 

 FAXON, W. 



1884. On the so-called Dimorphism in the genus Cambarus. Amer. Jour. Sci., 



vol. 27, pp. 42-44. 1884. 

 GALTON, F. 



1897. Note to the Memoir by Professor Karl Pearson, F. R. S., on spurious corre- 

 lation. Proc. Roy. Soc., vol. 60, pp. 498-502. 1897. 

 HAGEN, H. A. 

 1870. Monograph of the North American Astacidae. 111. Cat. Mus. Comp. Zool. 



Harvard Coll. 1870. Vol. 3, pp. 1-110, 11 plates. 

 HARRIS, J. A. 



1901. Observations on the so-called Dimorphism in the males of Cambarus Erichson. 



Zool. Anz., Bd. 24, pp. 683-689. 1901. 

 LEWENZ, M. A., and WHITELEY, M. A. 



1902. Data for the problem of evolution in man. A second study of the variability 



and correlation of the hand. Biometrika, vol. i, pp. 345-360. 1902. 

 MACDONELL, W. R. 



1904. A study of the variation and correlation of the human skull, with special 



reference to English crania. Biometrika, vol. in, pp. 191-244, pis. I-L. 1904. 

 PEARL, R. 



1906. Variation in Chilomonas under favorable and unfavorable conditions. Bio- 



metrika, vol. v, pp. 53-72. 



1907. A biometrical study of conjugation in Paramecium. Biometrika, vol. v, pp. 



213-297. 



PEARL, R. (with the assistance of OLIVE M. PEPPER and FLORENCE J. HAOLB). 

 1907a. Variation and differentiation in Ceratophyllum. Carnegie Institution of 



Washington Publication No. 58. 

 PBARSON, K. 



1897. Mathematical contributions to the theory of evolution. On a form of spurious 

 correlation which may arise when indices are used in the measurement of 

 organs. Proc. Roy. Soc., vol. 60, pp. 489-498. 1897. 



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