Calcium in the Blood. 



189 



which resembled those shown by Woodruff and Erdmann 1 to be 

 associated with endomixis in Paramecium caudatum were also 

 observed. Endomixis, however, if such occurs in the free living 

 state of Didinium, could not be carried out in this race during the 

 rhythmical periods owing to the lack of a definitive micronucleus. 



The amicronucleate state without doubt arose from some 

 irregularity during conjugation. Prandtl 2 in his study of the 

 cytology of conjugation in Didinium found individuals in which 

 all the micronuclei had become transformed into macronuclei, 

 but he thought animals so endowed were incapable of living. The 

 present study shows that they are viable but unable to undergo 

 processes such as encystment, conjugation, and endomixis which 

 are dependent largely upon micronuclear activity. 



94 (1676) 

 Calcium in the blood. 



By WM. C. THRO and MARIE EHN. 



[From Cornell Medical College, New York City.] 



One year ago we read a paper before this society on the 

 "Calcium in the Blood of Patients with Furunculosis and Acne." 

 We were aware that we obtained very large amounts of calcium in 

 the blood of some of the patients, but were unable to detect our 

 error. At that time we used the gravimetric method and with it 

 were unable to detect any calcium in the filter paper used, al- 

 though we made six attempts. This year, after perfecting our- 

 selves in the titration method for calcium determination, as given 

 by Halversan and Bergeim, 3 we found that some of the filter 

 paper we had been using contained considerable amounts of 

 calcium. We then decided to abandon the gravimetric method 

 and have used the titration method in obtaining the results given 

 here. 



1 Woodruff, L. L., and Erdmann, R., " A Normal Periodic Reorganization Process 

 without Cell Fusion in Paramecium," Jour. Exp. Zoal., 1914, xvii, 425-518. 



2 Prandtl, H., "Die Konjugation von Didinium nasutum," Arch.f. Protistenkunde, 

 1906, vii, 229-258. 



3 Halversan, J. O., and Bergeim, O., Jour. Biol Chem., 1917, xxxii, 159-170. 



