292 



O. HUG AND H. J. SCHLIEP 



Fig. 3(a) 



Fig. 3(b) 

 Fig. 3. — Contraction of leech muscles under continuous irradiation. 



(a) In Ringer solution aerated with 95 per cent O2 and o per cent C02- Dose-rate 6,600 

 r/niin, Irradiation time 120 min, Time marks: 1 min. 



X final length after 2hr irradiation. 



(b) Consecutive irradiation with two different dose-rates, firstly with 3,300 r/min to 

 46 min and secondly with 20,400 r/min to 20 min. 



During the first iiTadiation period the medium was aerated with 95 per cent O2 and 

 5 per cent CO2. 



Sh()rtl\- before the second irradiation the medium was exchanged for a solution aerated 

 with pure oxygen, therefore the nuiscle relaxed after the second irradiation. 



f start and | end of irradiation. Time marks: 1 min. 



