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: III. LIFE HISTORY OF A BACTERIAL CELL. Young cells grow, attain full size, multiply. Spore formation, analogy of spores to seeds of higher plants. Observed in many bacilli, few spirals, but not in micrococci. Sporogenic granules—their coalescence—the spore. Spore germination observed in but few instances. Bacillus subtilis, Cohn ; Bacillus butyricus, Praz- movski. Bacillus anthraci?, Koch; Bacillus megaterium, DeBary. Each spore gives rise to but one bacterial cell, and a cell develops but one spore. Spore formation, therefore, a means of reproduction, not of multiplication. Structure of a spore—dense, highly resistant cell-wall —the contents. Behavior of aniline dyes. Action of heat, cold, desiccation, chemicals. Their importance as resting or permanent forms. Position of the spore in the cell—median or terminal—with or without enlargment. Clostridium form— Drumstick or " Kopchen' form. Attempts at classification—Emlospore and arthro- ppore bacteria. Spore formation not the result of exhaustion of soil, but like the flower and fruit of plants represents the highest stage of development. It occurs only under favorable conditions— medium, temperature, oxygen. Asporogenic bacteria, result of unfavorable environment—influence of calcium. Multiplication of bacteria always takes place by division—one cell forms two and only two new cells. Threads—result from division of bacilli which remain adherent end to end by the undivided cell membrane. Diplococcus—Streptococcus—Staphylococcus. Division in two directions results in Tetrads. Division in three directions results in sarcines. Demonstration of, Sporogenic granules, threads, diplococci, Staphyl- ococci, streptococci, tetrads, sarcines. Spores, median and terminal. ...