The Mid-Winter Meetings. 191 



after about one hundred experiences. This modification of behavior occurs more 

 quickly in the male than in the female. It persists several weeks. 



Labyrinth tests are serviceable in the study of the dancing mouse only when the 

 avoidance of an unfavorable condition is demanded. Neither escape from con- 

 finement nor the obtaining of food furnishes satisfactory motives for the following 

 of a labyrinth path. The animal can find its way readily in a simple labyrinth 

 without the guidance of sight, smell and touch. Thus far my experiments indicate 

 the superiority of the female in the acquirement of labyrinth habits. 



Further Study of Variability in Spiders. By J. P. Porter. 



Results indicative of the variability of the instinctive behavior of spiders were 

 reported. 



The Effect of Distraction upon the Intensity of Sensation. By I. M. Bentley. 



Some Contributions to Applied Tone-psychology. By C. E. Seashore. 



Total Reactions. By E. H. Cameron 



Non-sensory Components in Sense Perception. By R. S. Woodworth. 



The familiar "staircase figure" presents a problem which may be stated in the 

 following terms: What is the diflPerence in conscious content between seeing the 

 figure as the upper side and as the lower side of a flight of stairs .'' Previous work 

 has shown that the difference cannot be ascribed to the stimulus; and inquiry by 

 the author showed that there was no detectable sensory imagery present in con- 

 sciousness that could serve to differentiate the two appearances. The two appear- 

 ances have, not different sensory qualities, but what may be called different "per- 

 cept qualities." Other non-sensory percept qualities are found in the subjective 

 grouping of dots, in a subjective rhythm, in perception of size and distance, and 

 in perception of things. A percept is not properly described as a synthesis of sen- 

 sation and image, for the image is often not present when the percept is perfectly 

 clear and definite. It is better to call the percept simply a mental reaction to sen- 

 sory stimulus, and to recognize that a reaction, as a new event, probably has a 

 quality of its own. This point of view is borne out by brain physiology, especially 

 by cases of word-deafness, etc., in which there is a loss of mental content, without 

 a corresponding loss of sensory consciousness. 



Visual Pressure Images: Their Nature and their Relations to the Visions due to 

 J Mescal and other Drugs. By E. B. Dei.abarre. 



Indications of Incipient Fatigue. By W. S. Monroe. 

 Benjamin Rush, M. D., On Mental Diseases. By I. W. Riley. 



p Section F. (Zoology) of the American Association for the Advancement of Science 

 and the American Society of Zoologists held joint sessions for the reading of papers, 

 during which the following papers, among others, were read: 



The Artificial Production of a Single Median Eye in the Fish Embryo by Means 

 of Sea-water Solutions of Magnesium Chlorid. By Charles R. Stockard, 

 Columbia University. 

 Fundulus embryos when developed in certain strength solutions of MgCl2 in 



