120 



PROTOZOOLOGY 



of a given species, the reduced number of chromatin granules 

 must be restored sometime before the next division takes place. 

 Calkins (1926) is of the opinion that "each granule elongates and 

 divides into two parts, thus doubling the number of chromo- 



FiG. 49. Division of Endamoeha blaltae as seen in life, X250 (Kudo). 

 The entire process took one hour and seven minutes. 



meres." Reichenow (1928) found that in Chilodonella cucullulus 

 the lightly Feulgen positive endosome appeared to form chroma- 

 tin granules and Kudo (1936) maintained that the large chroma- 

 tin spherules of the macronucleus of Nyctotherus ovalis probably 

 produce smaller spherules in their alveoli. 



In the elongated or miniliform macronuclei of a number of 

 ciliates, there occur, prior to and during division, 1-2 character- 

 istic zones which have been called by various names, such as 

 nuclear clefts, reconstruction bands, reorganization bands, etc. 

 In Euplotes patella, Turner (1930) observed before division, a 

 reorganization band consisting of an unstained zone ("reconstruc- 



