Cholinesterase and transport of sodium chloride through gills o/Eriochier sinensis (M.Edw.) 



10 . 



O 20 MINUTES. 60 8O 100 



Figure 7. Influence of TEPP {tetraethylpyrophosphate 



1.9 X io -3 m) on the JVaCl absorption of a gill of 



the crab and its reversal on the further addition of 



choline chloride io -3 M. 



20 



HIND END- 



Av. = 31 



1* 



.20 



-ro 



Av. = 1 4 



P<0-01 



p<0-01 



Figure 8. Absorption of 22 Na {expressed on basis of 

 activity per mg. of fresh tissue) by the isolated hind 

 ends (3 segments) of the larvae of Chironomus 

 plumosus influenced by eserine (io _3 m) and 

 tetraethylpyrophosphate (io -3 m) as compared with a 

 control. {Koch, Evans and Schicks, 19546.) 



23 



