4 Itagaki 



and this again in a considerably larger vessel. The latter was kept at a 

 uniform temperature, and besides containing the above-described apparatus 

 it served for holding small beakers containing different fluids for investiga- 

 tion, which were therefore kept at the same temperature as that of the 

 preparation upon which they were to act. 



The above modification of Magnus' apparatus, which was devised by 

 Professor Schafer, has two advantages over the original. In the first 

 place, one is able to change the immersion fluid without emptying the 

 tube in which the tissue is placed, so that the latter is completely sur- 

 rounded by fluid during the whole of the experiment. There is further no 

 risk of mechanically displacing the lever during the changing of the fluid, 

 and the temperature of the fluid undergoes no alteration at any time. 



Mode of Preparation O'f the Tissue. — The animals from which the 

 tissue was to be taken were always placed under chloroform. I found 

 that the excised uterus from such animals nearly always shows fairly 

 good contractions and regular rhythm. When completely anaesthetised 

 the animal was bled to death by cutting through both carotid arteries. 

 The abdomen was then opened freely, the intestine moved to one side, and 

 the uterus found. The vagina having been cut through, the cut end was 

 held by forceps and the cornua uteri separated from the adjoining 

 structures. The whole of the uterus was in this way removed from the 

 bodj^ and was then placed in cold Ringer solution. The Ringer which 

 I have employed throughout my experiments was prepared from Locke's 

 formula, and was usually that furnished by Parke, Davis & Co. The 

 formula is as follows : — 



NaHCOg 001 per cent. 



CaCl., 0-024 



KCl 0042 



NaCl 0-9 



No crlucose was added to the solution. 



As a general rule, a piece of one of the cornua was cut out and used as 

 a whole. The record was mainly one of the longitudinal fibres, for, as 

 Kehrer (7) and others have pointed out, the longitudinal fibres in the 

 uterus are much stronger than the circular and exhibit far more powerful 

 contractions. When larger animals were used, the whole of the cornu was 

 not taken, but only a longitudinal piece of the wall. In some experiments 

 portions of the uterus were used which had been kept immersed in Locke's 

 solution in an ice-chamber at a temperature of from 3° to 7° C. for from one 

 to three days. 



In all the animals which I have investigated the normal movements of 

 the uterine musculature are of two kinds, viz. : (1) regularly recurring 

 ryhthmic contractions and relaxations comparable to the " pendulum 



