G. REVERBERI 



331 



-AB 



CD-f- 



iG- 



k 



I 



Fig. 7. Nadi reaction (dotted) in developing eggs of Tubifex. a, c, e, 

 g, i, from the animal pole; b, d, f, h, j, from the vegetal pole; k, blastula 

 from the animal pole; /, hatched worm (Carrano and Palazzo, 1955). 



vented by the azide treatment, one can affirm that the zones of 

 the egg which are Nadi positive possess cytoclirome oxidase. If 

 this enzyme is locahzed in the mitochondria, these would ulti- 

 mately be segregated only in the ectodermic blastomeres. Similar 

 results have also been obtained by Mancuso ( 1955a ) in Physa. 

 Mitochondria segregated in the animal pole of the egg have been 

 actually observed by Ries and Gersch (1936) in Aplysia. How- 

 ever, these authors were not able to follow their destiny in the 

 following development. They supposed, probably founded on 



