70 VARIATION AND CORRELATION IN THE CRAYFISH. 



PEARSON, K. 



1902. Mathematical contributions to the theory of evolution. XI. On the influence 



of natural selection on the variability and correlation of organs. Phil. 

 Trans., vol. 200A, pp. 1-66. 1902. 

 SCHUSTER, E. H. J. 



1903. Variation in " Eupagurue prideauxi " (Heller). Biometrika, vol. n, pp. 191-210. 



1903. 

 WARREN, E. 



1897. An investigation on the variability of the human skeleton, with especial refer- 

 ence to the Naqada race discovered by Professor Flinders Petrie in his 

 explorations in Egypt. Phil. Trans., vol. 189s, pp. 125-227. 1897. 



1902. Variation and inheritance in the parthenogenetic generations of the aphis 



"Hyalopterus trirhodus" (Walker). Biometrika, vol. i, 129-151 1902. 

 YERKES, R. M. 



1901. A study of variation in the fiddler crab, Gelasimus pugilator Latr. Proc. 

 Amer. Acad. Arts and Sci., vol. xxxvi, pp. 417-442. 1901. 



