658 ^Journal of Comparative Neurology atid Psychology. 



researches on the color vision of the dog by Himstedt and IsTagel,^ hy 

 Samojloff and Pheophilaktowa/^ and by Orbeli.^ 



Since the resnlts obtained by these workers are important, it seems 

 desirable to give a brief account of their investigations. ^Kagel 

 believes, because of the very common occurrence of protective colora- 

 tion in animals, that ability to discriminate colors must be widely 

 distributed in the animal kingdom.^ He holds to this view especially 

 in the case of birds and mammals.''^ Believing, then, that the negative 

 results of Lubbock's experiments^ were inconclusive,^ Himstedt and 

 Nagel proceeded as follows. They first taught a poodle to bring them 

 a red ball (or rod) at the command "bring red." When the animal 

 had learned to do this, balls of blue, of gray, and of other shades of 

 red were added. From among these balls, the animal learned to 

 bring a very bright red at the first command, at the second, strawberry 

 red, then carmine, then, if no more reds were present, a bright orange 

 colored ball, and finally, if he was still commanded to bring red, he 

 would select a ball covered with Bismarck-brown of a distinctly 

 reddish hue. Thus the animal seemed to discriminate red and its 

 similars (for us), from other colors, and from grays. Later, Him- 

 stedt extended the training to other colors, with a like result. 



Samojloff and Pheophilaktowa pursued the following plan. They 

 first pasted a disk of green paper on the front of a small box in which 

 they placed a small bit of food. The dog was taught to get the food 



^Himstedt' F., and Nagel, W. A. A'ersuche iibei' die Reizwirknng verscbie- 

 dener Strahlenarten auf Menschen- uiid Tierangeu. Festschrift dcr AlhrccJit- 

 Ludtoigs-Universitdt in Freiburg. 1902. 



*Samojloff, a., und Pheophilaktowa, A. Ueber die Farbenwalirnebiuiiug 

 beim Hiinde. Zent. f. Physiol., Bd. 21, S. 1.33. 1907. 



^Yerkes, R. M., aud Mokgulis, Sergius. The metliod of Pawlow in animal 

 psychology. Psych. Bull., vol. 6, pp. 257-273. 1909. This review includes a 

 synopsis of the dissertation of Orbeli. Orueli, L. A. Conditioned reflexes 

 resulting from optical stimulation of the dog. Dissertation. St. Petershurg. 

 1908. (Russian.) 



^Nagei., W. a. Der Farbensinn der Tiere. S. 5. 1901. 



'S. 14. 



'Lubbock, J. On the senses, instincts and intelligence of animals, p. 277. 

 1888. 



"Nagel, W. A. Der Farbensinn der Tiere. S. 19-29. 1901. 



