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Procedures recommended for the study of bacteria
Procedures recommended for the study of bacteria Author:American Public Health Association Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: PROCEDURES RECOMMENDED FOR THE STUDY OF BAC- TERIA WITH ESPECIAL REFERENCE TO GREATER UNI- FORMITY IN THE DESCRIPTION AND DIFFEREN- TIATION OF SPECIES. BEING THE... more » REPORT OF A COMMITTEE OF BACTERIOLOGISTS TO THE COMMITTEE ON THE POLLUTION OF WATER SUPPLIES OF THE AMERICAN PUBLIC HEALTH ASSOCIATION. The various tests applicable for describing species of bacteria may be divided into two categories, as follows: Necessary tests, and those which in the present condition of bacterial science may be regarded as optional. The terms "necessary" and "optional" are here used with considerable hesitation, as many of the tests included among the optional are of importance and really necessary for the purposes of species differentiation in special cases. These tests, as grouped, however, are at the present time applicable to a great majority of the species known, those classed as necessary being of primary importance and of the greatest general utility. NECESSARY INFORMATION AND TESTS. Information with regard to the following features and properties of any species of bacteria that is being studied is held by the committee to be necessary and to form the indispensible basis for conclusions as to the characters and relationships of that species. I. Source and habitat. II. Morphological characters. 1. Form. 2. Dimensions. 3. Manner of grouping and arrangement in the growths. 4. Staining powers, (a) with watery dyes, (b) by Gram's method. 5. Presence or absence of capsule. 6. Presence or absence of flagella (motility). 7. Spore formation and differentiation of spores from deposits and vacuoles within the cell. 8. Tendency to pleomorphism. 9. Involution and degeneration forms. III. Biological characters. A. Cultural characteristics, mode of gro...« less