138 



Scientific Proceedings (113). 



The purpose of the present paper is to record the discovery 

 in January, 1920, of a hitherto undescribed form of Paramecium. 

 It has now been extensively studied in pedigree cultures for more 

 than a year and during this time it has bred true. I therefore 

 definitely designate it a new species, Paramecium calkinsi, in 

 recognition of the fact that Professor G. N. Calkins of Columbia 

 University introduced students of the Infusoria to exact, daily 

 isolation, pedigree culture methods. 



The general body form of the new species places it at once in 

 the bursaria-putrinum group, but its micronuclei both in structure 

 and number are identical with those of Paramecium aurelia. 

 In brief, Paramecium calkinsi represents the 'aurelia' type of 

 micronuclear complex in the 'bursaria' group of species. 



Details of the structure and life history of Paramecium calkinsi 

 will appear in the Biological Bulletin. 



65 (1647) 



The yeast test as a quantitative measure of vitamine. 



By WALTER H. EDDY, HATTIE L. HEFT, HELEN C. STEVENSON and RUTH 



JOHNSON. 



[From the Department of Physiological Chemistry, Teachers College, 

 Columbia University and the Department of Pathology, New 

 York Hospital, N. Y. City.] 



The details of this paper will be reported in full in another 

 publication. The experiments reported covered the following 

 points: 



I. A comparison of yeast test results (Funk 1 technique) with 

 the material used by Osborne and Mendel 2 in a feeding test with 

 rats. The test was shown to merely approximate the results of 

 the feeding test but when the dilution of the extracts were such 

 that the content of one gram was present in 250 c.c. of water the 

 agreement was much more exact. This result agrees with Funk's 

 findings that the extract test must fall within the steep part of 

 the curve of stimulation if it is to be used comparatively. 



1 Funk, C, and Dubin, H., Journ. Biol. Chem., 1920, xliv, 487. Ibid., Proc. 

 Soc. Exper. Biol, and Med., 1920, xvii, 175. 



2 Osborne and Mendel, Journ. Biol. Chem., 1920, xli, 451. 



