RESPIRATORY METABOLISM OF PLAXARIA AGILIS. 



215 



TABLE V. 



All Planaria starved 33 days before experiment. Temp. 20 C. 30 days before and 

 during the tests. One half of the total number of worms were fed beef liver 

 24 hours before beginning of the tests. Heads of all the worms were cut off 

 one hour after feeding. 20 worms in each bottle. 



of catabolism which accumulated during the period of life in 

 low oxygen. 5 In the absence of a complete chemical study of 

 the metabolism of Planaria the results await an adequate ex- 

 planation. 



6 In his monograph "Respiratory Exchange of Animals and Man," Chapter VI., 

 page 83, Krogh states that, according to Lesser (Zeltschr.f. Biol., vol. 54, pp. 1-17), 

 earthworms after living in the absence of oxygen, when returned to air show an 

 increased rate of oxygen consumption, due to oxidation of accumulated oxidizable 

 residues during the anaerobic period. In fact Lesser found just the opposite 

 and states definitely, pp. 11-12: "Durch Respirationsversuche . . . wurde 

 festgestellt, das der respiratorische Quotient beim Regenwurm ... in der 

 Erholung nach vorausgangener Anoxybiose erhoht ist gegeniiber dem normalen. 

 Es findet mithin in der Erholung eine vollige Verbrennung . . . der friiher als 

 Hauptprodukt der Anoxybiose gefundenen Fettsaiire nicht statt." 



