not exceed 5 p. с Similarly as in the first group controls with muscle implant- 

 ation луеге performed. 



The oxygen consumption was measured in Warburg's respirometer by the 

 direct Warburg method. COg in simplified vessels was absorbed by 10 p. c. 

 KOH in the central chimney. The insects were put into tubes of black paper 

 shut from both sides by a silon net; they remained relatively quiet, луЬ1сЬ was 

 probably due the the subdued illumination. The vessels were submerged 

 into a water bath of 25°C and were immobile similarly as manometers. The 

 measurings were made in one hour's intervals, 4—5 times a day; greater 

 oscillations in the upper limit due to the movement of the specimens and 

 irritation after being put into the vessels (most often in the first measurement) 

 were excluded from the average count. Excluded were also those individuals 

 who perished (in the most part on bacterioses) during the three days after 

 the experiments were finished. Under these conditions reproduceable results 

 were obtained in spite of a certain variability caused by the movement of bugs 

 during the measurement and by other factors. Except the time of measur- 

 ements the bugs were kept isolated in glas tubes containing lime-seeds and 

 water at 25°C. 



In the first group of experiments the oxygen consumption was measured 

 in 24 specimens with the с allatum implanted and in 14 controls; the second 

 group included 17 experimental specimens and 15 controls. The results are 

 statistically significant, with the probability of accident P 0-05 p. c, in some 

 cases O'l p. c. 



The results represented in diagrams I and II can be summarised as follows: 

 in the days after the moulting the normal starving P. apterus females show 

 a gradual oxygen decrease per Individuum as well as per g/hour. The decrease 

 is in connection neither with the operation nor with the accompanying narcosis. 

 In castrated females the decrease of oxygen consumption in the first 3 days 

 after the moulting seems to be more rapid than in normal individuals, 

 from the 5th day after the moulting, (the 3rd day after the muscle implant- 

 ation) a slight increase of oxygen consumption could be observed in nearly all 

 individuals, while their weight continually diminished. Both observations 

 need to be re-examined on a larger material and if confirmed analysed in more 

 detail. For the present work it is important to know that both normal and 

 castrated females show a continual oxygen decrease after the implantation 

 of muscle in 28 out of 29 cases. 



On the other hand, after an active с allatum implantation a distinct rise 

 of oxygen consumption can be registered in 17 out of 24 cases (71 p. c), in the 

 other 7 specimens — except one — the consumption remains practically on the 

 same level, so that the average shows a real increase both per individuum 

 and per gram/hour. This post-implantation increase, however, does not take 

 place in castrated specimens луЬеге in 1 1 out of 17 individuals (65 p. c.) the fall 



149 



