A STATISTICAL STUDY OF GENERIC CHARACTERS IN 

 THE COCCACE^: * 



C.-E. A. WINSLOW AND ANNE F. ROGERS, 



ASSISTED BY 



ELIZABETH STRONGMAN, BERTHA I. BARKER, MARY D. HALE, AND 



ANNIE P. HALE. 



I. PURPOSE OF THE INVESTIGATION. 

 II. METHODS or THE INVESTIGATION. 



1. Isolation of Cultures. 



2. Selection of Characters for Study. 



3. Morphological Characters. 



4. Cultural Characteristics. 



5. Biochemical Reactions. 



III. RESULTS OF THE INVESTIGATION. 



1. Habitat. 



2. Grouping of Cells, and Dimensions. 



3. Gram Stain. 



4. Surface Growth. 



5. Fermentation of Carbohydrates. 



6. Reduction of Nitrates. 



7. Optimum Temperature. 



8. Chromogenesis. 



9. Gelatin Liquefaction. 



IV. CONCLUSIONS FROM THE INVESTIGATION. 



1. Foundation of Subfamilies and Genera among the Cocci. 



2. Systematic Summary. 

 V. REFERENCES. 



I. PURPOSE OF THE INVESTIGATION. 



There has been placed in the hands of the biologist within the 

 last few years a new instrument of research of the highest value. 

 This is the statistical method, first suggested for the study of human 

 characteristics by Quetelet (1846), specifically applied to the bio- 

 logical problems of variation and heredity by Galton (1889), and 

 extended and developed in detail by Pearson and his pupils. The 

 most important papers on this subject may be found in the files of 

 the Philosophical Transactions of the Royal Society of London and 

 in Biometrika. Admirable brief summaries have been prepared 

 by Pearson (1900) and Bigelow (1904). 



* Received for publication April 3, 1006. 



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