74 



Scientific Proceedings (57). 



3. The rhythms have been shown to be independent of environ- 

 mental changes and due to inherent phenomena in the cell. 1 

 The present cy tological study demonstrates that : 



1 . The rhythms in the division rate of Paramaecium are the 

 physiological expression of profound nuclear changes. 



2. These periodic nuclear phenomena involve the formation 

 of a complete new nuclear apparatus by a definite sequence of 

 morphological changes disintegration of old macronucleus; multi- 

 ple division of micronuclei, formation of new macronuclear Anlagen 

 which simulate typical conjugation. This results in the reorgan- 

 ization of the cell without the fusion of two animals. 



This nuclear reorganization is evidently a normal substitute for 

 typical conjugation in this race, but does not preclude its occur- 

 rence for the latter process has occurred in subcultures from this 

 race subjected to environmental conditions suitable for its con- 

 summation. 2 



Details of this remarkable process, together with a discussion 

 of its theoretical importance from the standpoint of the sexual 

 potentiality of unicellular organisms and the physiological be- 

 havior of long pedigreed races of Infusoria, will be presented in 

 another paper. 



44 (861) 



The aggressin-like action of anaphylatoxin. 



By Hans Zinsser and J. G. Dwyer. 



[From the Department of Bacteriology, College of Physicians and 

 Surgeons, Columbia University.} 



In the course of experiments upon the repeated injection of 

 anaphylatoxin into guinea-pigs the writers noticed a phenomenon 

 which suggested to them that the anaphylatoxic substances may 

 possibly possess properties similar to those described by Bail for 

 his "aggressins." In the earlier experiments the anaphylatoxins 

 were prepared with typhoid bacilli by emulsifying one slant of 

 the bacteria in 8 c.c. of fresh guinea pig complement and allowing 



1 Woodruff and Baitsell, Jour. Exper. Zool., XI, 1911, p. 339. Erdmann, Archiv. 

 fur Protistent., XXIX, 1913, p. 118. 



2 Woodruff, Jour. Exper. Zool., XVI, 1914, p. 237. 



