ILLUSTRATIONS 
FIG. PAGE 
1. Bacilli, cocci, and spirilla.25 
2. Pneumococci, showing capsules.26 
3. Typhoid bacilli, showing flagella.27 
4. Tetanus bacilli, showing spores.28 
5. Hot-air sterilizer.42 
6. The Arnold sterilizer.43 
7. The autoclave.45 
8. Instrument employed in applying Dakin’s solution to 
wounds .50 
9. Ehrlich’s theory of immunity.68 
10. Side-chains, with bacterial poison attached, cast off free 
into circulation.69 
11. Illustration of Ehrlich’s theory in case of diphtheria . 70 
12. Ehrlich’s conception of a toxin molecule.72 
13. The receptor of second order (agglutinins and precipitins) 73 
14. The receptor of third order (bacteriolysis, hemolysin) . 74 
15. Apparatus for staining.84 
16. Microscope and artificial illumination.86 
17. Miscellaneous glassware.93 
18. Making a transfer of a culture.95 
19. Tubing the media.102 
20. Two types of water-baths.112 
21A. The incubator .115 
21B. Special tube for obtaining blood for Wassermann . . 117 
22. Staphylococcus.120 
23. Staphylococcus pyogenes aureus.121 
24. Streptococcus pyogenes.126 
25. The meningococcus.135 
26. The gonococcus .139 
27. Bacillus coli .143 
28. Bacillus typhosus.146 
29. Dysentery bacilli.157 
30. Bacillus welchii .163 
17 
