Waste material in the tissues is carried off by the return blood in the veins and also by the lymphatics. These are in reality the scavengers of the body, both the lymphatic vessels and glands, performing important functions for the good of the economy. They are found beneath the skin and in the subcutaneous tissue, also along the course of the great veins. The lymphatics far exceed the veins in number and perform a function similar to the veins, gathering waste material from the tissues, also the digested food called _chyle_, from the stomach and intestines. The lymphatic vessels, also the lacteals which absorb the chyle, all pass through glands, which are extremely numerous, where certain deleterious substances are extracted from the lymph before it is emptied into the blood stream. The lymphatic glands in performing their function as filters often become inflamed and when large numbers of pathogenic bacteria, or very virulent ones are contained in a gland, abscess formation results just as it would in any tissue so invaded. CHAPTER II +SURGICAL BACTERIOLOGY+ A _microorganism_ or _microbe_, some species of which cause all disease, is a minute plant or animal too small, as a rule, to be visible to the naked eye. The word _germ_ may be used to designate any microorganism, but it has so many other meanings and has been so loosely employed even in this sense, that it cannot be used for accurate scientific description. _Bacteria_ are minute plants on the order of fungae, many of which are able to produce fermentation, decomposition or disease. Although the word _bacterium_ by derivation has the same meaning as _bacillus_ and indicates a rod shaped fungus, it has been so loosely employed that it may very well be applied to the entire germal family, retaining the word bacillus in the narrower sense. +Description of Bacteria.+ _Schizomycetes_ is the name given all the bacteria of putrefaction and disease, the former being called _saprophytic_ and the latter _pathogenic_.