1 86 "Journal of Comparative Neurology and Psychology. 



At the ninth annual nfieeting of the American Physiological Society, the follow- 

 ing papers of special interest to neurologists were presented: 



Functions and Structures in Amoeba proteus. By C. F. Hodge and O. P. Del- 

 linger. 



The material of this study consisted of Amoeba which had been killed in vari- 

 ous ways and stained in toto, and of series of sections stained by different methods. 

 The function of contraction is effected by a meshwork of fibrillae, these being woven 

 into heavy trabeculse with wide intertrabecular spaces in the interior (endosarc), 

 and united to form a fine web over the exterior (ectosarc). This mechanism is 

 all that can be demonstrated to account for movements: locomotion, ingestion, 

 egestion, contraction of vacuole, division of nucleus and of entire body, and internal 

 circulation. This tissue forms, without essential differentiation, the outer mem- 

 brane (ectosarc), trabeculre, wall of contractile vacuole and of all food vacuoles, 

 nuclear membrane and nuclear reticulum. Movements are coordinated, but no 

 differentiation of conducting fibrillae has been clearly demonstrated. This tissue, 

 when supplied with necessary nutrient substances, must possess the function of 

 growth. The function of digestion is mediated in all animals by gland cells, charac- 

 terized by zymogen granules. The only structure in Amoeba which is definitely 

 granular is the nucleus. Sections show nuclear granules apparently passing out of 

 the nucleus into the food vacuoles. These two mechanisms, together with a circu- 

 lating fluid, account for all the functions of the animal, reproduction being undif- 

 ferentiated from growth, and respiration, excretion and circulation being effected 

 by movements of the whole body and supplemented by a similar action of the con- 

 tractile vacuole. Except as noted above, sections reveal no difference between 

 ectosarc and endosarc. 



Physiological Reactions of Physa. By J. Dawson. 



Vasomotor Reflexes. By W. T. Porter. 



The Cause of Treppe. By F. S. Lee. 



Methods of Studying Fatigue. By F. S. Lee. 



The Functions of the Ear of the Dancing Mouse. By R. M. Yerkes. 



Both the static and the acoustic functions of the ear of the dancer differ markedly 

 from those of the common mouse. Orientation and equilibration are fairly good. 

 There is no evidence of turning dizziness. The whirling movement which is char- 

 acteristic of the race appears as soon as the young mouse is strong enough to stand. 

 It is somewhat more pronounced in the female than in the male, and it occurs 

 chiefly toward evening. With respect to this movement there are three well defined 

 groups of dancers: those which almost always whirl toward the right, those which 

 whirl toward the left, and those which whirl now one way now the other. At 

 present,! have no satisfactory evidence of the inheritance of the tendency to whirl 

 in a certain way. 



Direct and indirect methods of testing acoustic sensitiveness have given nega- 

 tive results in the case of the adult, but the young dancer responds to certain sounds 

 for from two to five days during the third week of life. This brief period of sen- 

 sitiveness to sound is preceded by a marked change in behavior. 



The Effect of Section of One Vagus upon the Secondary Peristalsis of the Oesopha- 

 gus. By S. J. Meltzer and J. Auer. 



