metric determination superior to paper chroma- 

 tography in detecting the organophosphate, Bay- 

 tex, in bird tissues. 



DDT degradation in the animal body produces 

 several metabolites, a principal one being DDE. 

 Ketone is produced as a metabolite of DDT in cer- 

 tain insects, but has never been reported in warm- 

 blooded animals. Gas chromatography of an un- 

 known compound in control blood from the same 

 animal and laboratorj-synthesized ketone indi- 

 cated that ketone could be so produced. DDT 

 and DDE in laboratory rats produced the same 

 metabolite, but it was not produced by homologous 

 "DDJR'" and "DDXr" in rats, implying that 



the newly discovered metabolite is actually derived 

 from DDE. Thus, a "missing link" in the degra- 

 dation of DDT can be filled in. 



The toxicity of eldrin, aldrin, dieldrin, chlor- 

 dane, toxaphene, and DDT in mallards, bobwhite 

 quails, and ring-necked pheasants has been tmder 

 determination at the Patuxent Center for several 

 years. A new protocol for testing pesticide toxic- 

 ity in penned birds has been developed. It yields 

 quantitative toxicity ratings of chemicals in rela- 

 tion to each other, and the amount of each chem- 

 ical needed to produce a prescribed level of mor- 

 tality imder given conditions. 



A young bald eagle held at the Patasent Wildlife Research Center for use in long-time study of DDT residue accumulation. 



51 



