124 Al^Y.}[}[ErRIC ANALYSLS 



The experiments of Gause, Sniaragdova and Alpatov 

 (1938) to be reported here, consisted in the analysis of 

 the action of the optical isomers of cinchonine on the 

 rate of the following functions of the infusorian Para- 

 mecium caudatiim: (1) The feeding rate, as measured by 

 the number of food vacuoles formed in water suspensions 

 of india ink; (2) The velocity of expulsion of gastric 

 vacuoles; (3) The division rate; (4) The velocity of loco- 

 motion in thin glass tubes, according to the method of 

 Glaser (1924) ; (5) The death rate, death being diagnosed 

 by the complete cessation of all motion. 



It was found that the stereo-coefficient of action of 

 cinchonine (a) was of the same order of magnitude (about 

 1.3) in the case of the inhibition of the following three 

 functions : the formation of the gastric vacuoles, the ex- 

 pulsion of these vacuoles, and the division rate. In other 

 words cinchonine inhibits some susceptible system which 

 controls these three functions. The gastric vacuoles in 

 paramecia separate from the gullet, being, so to say, 

 pulled away by the active protoplasm (cf. Metalnikoff, 

 1910 and Bozler, 1924). Their formation and their ex- 

 pulsion are evidently connected with the degree of activ- 

 ity of the protoplasm. These two functions, as Avell as 

 the rate of division, are, therefore, expected to be con- 

 trolled by the rate of metabolism in the endoplasm of the 

 Paramecium. In all probability optically isomeric cin- 

 chonines, inhibiting one of the phases of metabolism in 

 the endoplasm, depress all the three functions together. 



On the other hand, the cessation of the motion in para- 

 mecia by cinchonine is evidently connected with the pois- 

 oning of the svstem of locomotory cilia. This svstem is 

 localized in the ectoplasm (cf. Kalmus, 1931). The stereo- 

 coefficient of action of the optical isomers of cinchonine 

 is significantly ditferent from that previously recorded, it 

 reaches 1.98 (the left isomer being, as before, more pow- 

 erful than the right). These data are presented in 

 Table 21. 



