i MEETING OF INSPECTORS OF APIARIES. 
dom, as the trees, shrubs, flowers, and grasses, and we may for con- 
venience refer to these plants as the visible flora. There is also an 
invisible flora, made up of the plants we can not see except with the 
aid of the miscrope. This flora includes the very minute plants: 
referred to as bacteria, and also the yeasts and some fungi. The dis- 
tinct species of plants which belong to the invisible flora outnumber 
by far those which are visible to the naked eye. These microscopic 
plants are found upon the surface of the animal body and along the 
digestive tract; they are found in the soil, in the food we eat, and in 
the water and milk we drink, but are not found within the normal 
tissues of animals and higher plants. 
HOW BACTERIA ARE STUDIED. 
The morphology or structure of bacteria is studied with the aid of 
a microscope of high*magnification. Since the number of distinct 
species of bacteria is so extremely large, and since the shapes assumed 
by them are so few, it is obvious that many different kinds must look 
alike under the microscope. This is a point of considerable value in 
connection with bee-disease work, since in some cases attempts have 
been made by the use of the microscope alone to determine what 
species of bacteria was causing certain diseased conditions. With 
our present knowledge it is not possible to make a positive diagnosis 
of these diseases with the microscope alone. With the microscope we 
are able to determine usually only the genus to which any bacterium 
belongs. If we are trying to identify Bacillus alvei, for example, we 
are able with the microscope alone to say only that it is a Bacillus, 
since it is seen to be a straight rod. Some other means is necessary to 
determine the species (a/ve/) to which it belongs. For this purpose 
we use artificial media or “ soils” in which pure cultures of the bac- 
teria are inoculated or planted. 
The media in common use are bouillon and sugar-free bouillon, 
gelatin, agar, and sugar-free bouillon to which has been added small 
amounts of various sugars known in chemistry as glucose, lactose, 
saccharose, maltose, and levulose. In addition to these media, use is 
made of potato, milk, and milk to which litmus has been added, so 
that the reaction—whether acid, alkaline, or neutral—may be noted. 
The bouillon is prepared from beef juice to which some peptone and 
salt are added. Sugar-free bouillon is similar, except that the muscle 
sugar has been removed. Gelatin is made from pure sheets of gel- 
atin somewhat similar to that used in cooking, to which bouillon is 
added. The bouillon affords the food for the bacteria or other small 
plants, while the gelatin keeps the medium solid at ordinary tempera- 
tures. Agar-agar (or simply agar) is the dried stem of a certain sea- 
weed which liquefies on heating; to this is added bouillon, as.in the 
