180 



METABOLIC HORMONES 



which probably regulate the release of hormone into the blood, 

 the crab, Gecarcinus lateralis, loses "its normal ability to vary the 

 type and rate of metabolism". Indications of this are seen in a 



O 



0.12- 



0.10- 



008- 



0.06- 



0.04- 



0.02- 



PUGILATOR 



WOODS HOLE 



PUGILATOR 



(FLORIDA] 



PUGNAX 



Fig. 5-6. Effects of eyestalk removal and subsequent injection of 

 eyestalk extract on the average rate of daytime oxygen consump- 

 tion of two fiddler crabs, Uca pugilator and U. pugnax, over a period 

 of some weeks after treatment. Removal of one eyestalk removes 

 less of the respiration-inhibiting hormone than does that of 

 two; the injected extract is not strong enough fully to replace it 

 (from Edwards, 1950). 



normal respiratory quotient and a low and relatively invariable 

 respiratory rate, compared with normal crabs (Fig. 5-7^). The 

 greatest increases in oxygen consumption in eyestalkless crabs are 



