References 369 



736. UEXKULL, J. VON, 1900. Die Wirkung von Licht und Schatten 



auf die Seeigeln. Ibid., Bd. 40, S. 447. 



737. 1900. Ueber die Stellung der vergleichender Physiologic 



zur Hypothese der Tierseele. Biol. Cent., Bd. 20, S. 497. 



738. ULRICH, J. L., 1915. Distribution of effort in learning in the 



white rat. Behavior Monographs, vol. 2, no. 5, serial no. 10. 



739. VASCHIDE, N., and ROUSSEAU, P., 1902. Etudes experi- 



mentales sur la vie mentale des animaux. Rev. scient., 

 t. 19, pp. 737, 777- 



740. - - 1903. Etudes, etc. Ibid., t. 20, p. 321. 



741. VERWORN, M., 1891. Gleichgewicht und Otolithenorgan. 



Pfliigers Arch., Bd. 50, S. 423. 



742. 1899. Psycho-physiologische Protistenstudien. Jena. 



743. - - 1899. General physiology. Trans, by F. S. Lee. 



London. 



744. VIGNIER, M. P., 1909. Mechanisme de la synthese des im- 



pressions lumineuses recueillies par les yeux composes des 

 dipteres. C. r. Acad. Sci., Paris, t. 148, p. 1221. 



745. VINCENT, S. B., 1912. The mammalian eye. Jour. Animal 



Behav., vol. 2, p. 249. 



746. - - 1913. The function of the vibrissae in the behavior of 



the white rat. Behavior Monographs, vol. i, no. 5. 



747. 1915- The white rat and the maze problem, I. The 



introduction of a visual control. Jour. Animal Behav., vol. 



5, P- I- 



748. 1915. The white rat, etc., II. The introduction of an 



olfactory control. Ibid., vol. 5, p. 140. 



749. - - 1915. The white rat, etc., III. The introduction of a 



tactual control. Ibid., vol. 5, p. 175. 



750. 1915. The white rat, etc., IV. The number and dis- 

 tribution of errors : a comparative study. Ibid., vol. 5, p. 367. 



751. WAGER, H., 1911. On the effect of gravity upon the movements 



and aggregation of Euglena viridis Ehr. and other micro- 

 organisms. Phil. Trans. Roy. Soc., London, vol. 201 B, 



P- 333- 

 7510. WAGNER, G., 1904. On some movements and reactions of 



Hydra. Quar. Jour. Micr. Sci., vol. 48, p. 585. 

 7516. WAGNER, W., 1906. Psychobiologische Untersuchungen an 



Hummeln. Zoologica, Heft 46, Bd. 19, 2 Lief. 



2B 



