ioi8 



INDEX 



Hormones, 147 

 Horse pox, 857 

 Horse sickness, 863 

 Hyacinth, soft rot of, 985 



Wakker's disease, 979 

 Hydrogen, displaceable, 160 



as food, 222, 224, 226 



oxidation in soil, 351, 377 



production in soil, 375 



sulphide as food, 224 

 Hydrogen ion concentration, determina- 

 tion of, 165 



of soils, 356 



theory of, 162 



Hydrolyzing enzymes, 208, 209 

 Hydromel, 629 

 Hydrophilus pistaceus, 919 

 Hyperimmune serum, 746 

 Hypha, 36 

 Hyphomycetes, 251 

 Hyposulphite oxidation, 201 



ICE CREAM, 512 



increase of bacteria during storage, 



poisoning, 586 

 Immunity, acquired, 687, 697, 725 



active, 697, 725 



definition of, 684 



exhaustion theory of, 721 



familial, 688 



general, 684 



individual, 688 



of insects, 946 



natural, 687, 725 

 factors of, 688 



noxious retention theory of, 721 



passive, 697, 698, 725 



phagocytic theory of, 723 



plants, 950 



racial, 687 



side chain theory of, 722 



theories of, 721 

 Imperfect fungi, 40, 61 

 Index, opsonic, 712 



percentage, 713 



Index, phagocytic, 712 

 Indigo, 658 



Indirect division of nucleus, 28 

 Indol, production of, 241 

 Infantile kala azar, 880 

 paralysis, 864 



control of, in London, Canada, 



763 

 Infection, air-borne, 664 



animal carriers of, 667 



by biological agents, 773 



cause of, 675 



contact, 668 



defined, 659 



droplet, 665 



dust, 665 



factors influencing, 674 



food, 581, 666 



human carriers, 668 



manner of entering body, 664 



milk-borne, 467, 666 



number of organisms involved in, 

 674 



resistance against, 675 



routes of, 669, 754 



soil, 666 



sources of, 664 



staphylococcic, 792 



streptococcic, 795 



variations of, 672 



virulence of, 674 



water-borne, 666 

 Infectious mastitis, 789 

 Inflammatory processes, 693 

 Influenza, 822 



Influenza-pneumonia vaccine, 738 

 Infusoria, characteristics, 139 



parasitic, 899 

 Inheritance of disease, 685 

 Inorganic food preservatives, 555 

 Insects, diseases of, 905 



immunity in, 946 



pathology of, 946 

 Inspected milk, 432 

 Intercellular relations, 300 

 Intestine, microorganisms of, 596 



