34 THE MICROSCOPE. Mar. 



9. Anthrax. Bacillus anthracis. Thickness 1-25,000 inch. 



10. Relapsing fever. Spirochsete dbermaicri. Spirilla from the blood. 



11. Influenza (La Grippe). Dia. 1-110,000 inch. 



12. Pus. Staphylococcus pyogenes aureus. Dia. 1-35,000 inch. 



13. Yeast fungus. Dia. 1-3,000 inch. 



14. Glanders. Bacillus mallei. Dia. 1-60,000 inch. 



15. Pneumonia. Pneumococcus friedlander. Capsulated micrococci. 



16. Consumption. One tubercle containing spores. 



17. Typhoid. Bacilli containing spores. 



18. Anthrax (malignant pustule). Bacilli from blood. 



19. Saliva. Various forms found in the mouth. 



20. Asiatic cholera. Some joined in threads and some S shaped. 



These disease germs shown id the 20 figures and enu- 

 merated in the accompanying list are so small as to test 

 microscopical skill to the utmost. None but the highest 

 powers and most costly objectives will reveal them and 

 then only by means of stains and other aids. Some bac- 

 teriologists deny that the microscope alone can identify 

 these different bacteria one from the other. Consequently 

 they resort to what they call cultures in which they mul- 

 tiply indefinitely their numbers. The appearance and 

 behavior of these colonies consisting of millions of single 

 bacteria furnish a sure clue to their species. The eff'ects 

 produced in rabbits and other animals are also taken as 

 proofs of their identity. As then the forms are so illu- 

 sive even under the highest powers, they have not yet 

 been fully described and classified morphologically, or 

 in respect to the forms they present to the eye. While, 

 therefore, the pictures we give are to some extent true, 

 there are other bacteria not pictured here which, when 

 pictured will not present a different appearance from 

 some of these. In some cases of bacteria which look 

 alike to the eye, one will stain easily with Aniline while 

 another will not. For instance the Bacillus tuberculosis 

 resists the stains which are effective with many species 

 and requires special methods. Some bacteria will mul- 

 tiply when placed upon slices of raw potato, others will 

 not. Some grow upon the surface of bouillon, others 



