136 R - J- FLIPSE 



casion the sperm were found immotile after the preparative wash- 

 ing. Rather than discard the preparation, we followed through the 

 outlined experimental procedure to determine whether immotile 

 sperm show metabolic activity. To our surprise the C 14 2 produc- 

 tion by immotile sperm was almost twice that normally observed 

 with motile sperm, whereas the yield of labeled lactate was one- 

 fourth the normal amount. This, I think, illustrates the importance 

 of specifying the age, motility, method of preparation, and other ap- 

 propriate conditions which might apply in studies of the metabolism 

 of spermatozoa. 



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