102 



THE PHYSIOLOGY OF EARTHWORMS 



10 15 20 25 



Partial pressure of oxygen, .mm Hg 



(a) 



100 



mm Hq 



(b) 



Fig. 32. Oxygen dissociation curves of haemoglobin from Lum- 

 bricus and Allolobophora. (a) shows the effect of temperature on the 

 curves; A. referring to Allolobophora, L. to Liimbricus. (b) shows 

 the effect of pH on the dissociation curve of Lumbricus. (a) from 

 Haughton, Kerkut and Munday, 1958, (b) from Manwell, 1959, 

 (by permission of the Wistar Institute). 



