1148 



REPRODUCTION 



longitudinally to a lever as in that experiment, and make all the arrange- 

 ments mentioned there. After a longer or shorter interval spontaneous 

 rhythmical contractions of the uterus ring commence. As soon as they 

 are well established, and while the contractions are being recorded on a 

 very slow drum, replace the Ringer's solution by serum, defibrinated 

 blood, blood prevented from coagulating by citrate solution (p. 66), or 

 hirudin, or by plasma, and note the effect. The serum or plasma may 

 be diluted to a known amount with Ringer's or Tyrode's solution before 



Fig. 490- At ii Ringer's solution was replaced by citrate plasma. At 39 Ringer's 

 solution was replaced by hirudin plasma ; at 41 by the corresponding hirudin 

 serum. 



application to the segment. Wash away the serum or plasma thor- 

 oughly with Ringer's solution. Replace the Ringer's solution by 

 adrenalin solution (i : 10,000,000). Note whether the tone of the ring 

 (as shown by its permanent shortening) or the rate and strength of the 

 contractions are increased. While a tracing is being taken repeat the 

 observation, adding a larger proportion of adrenalin. Determine in 

 what concentration a distinct effect is produced. A sufficient number of 

 uterus rings can be obtained from one animal for a considerable number 

 of experiments. 



