I 



LIST OF ILLUSTRATIONS 



PLATE ILLUSTRATIONS 



KO. PAGE 



1. Colonies of Acid- Fast Bacilli from Butter (Petri- Rabinowitsch), and 



Milk (Moeller) ..... Chromo. frontispiece 



2. Constituent Elements of Milk .... 



3. Udder of Cow ...... 



4. Air Pollution in Towns, and Tyndall's "Raft Theory" 



5. Sources of Contamination in Milk — Air 



6. Sotu-ces of Contamination in Milk — ^Water 



7. Method of Drawing and Storing Sterile Milk . 



8. Pakes' Counting Disc, etc. .... 



9. Flasks for Anaerobic Cultivation 



10. Comparative Air Plates — (a) Country Air, (J>) London 



Air ...... Between pp. 100 and loi 



11. Comparative Air Plates — {c) Labourer's Cottage in 



Bucks, {(£) Tenement House in London . • » ,, n 



12. Comparative Air Plates — {e) London Milk-Shop, (/) 



Country Milk-Cooling Room . . • m « » 



13. Apparatus for Bacteriological Examination of Air . To face page 104 



1 4. Typical Milk Plates on Nutrient Agar (a) and (^) "j 



\ Between pp. \yoand 131 



15. Typical Milk Plates on Nutrient Agar {c) and {d) J 



16. Typical Milk Plates on Nutrient Agar (e) and (f)^ 



y „ 132 and 133 



17. Typical Milk Plates on Nutrient Agar (g) and (h)) 



18. Relative Distribution of Organisms in (i) Set Milk 



and Cream ; (ii) Separated Milk and Cream . To face page 144 



