Our bacteriologists, of course, are quite confident that in the future more practical results will be obtained along this line than in the past. If it is true that cheeses are ripened by bacteria; if it is true that different qualities in the cheese are due to the growth of different species of bacteria during the ripening, it would seem to be possible to obtain the proper kind of bacteria and to furnish them to the cheese maker for artificially inoculating his cheese, just as it has been possible to furnish artificially cultivated yeasts to the brewer, and as it has become possible to furnish artificially cultivated bacteria to the butter maker. We must, however, recognise this to be a matter for the future. Up to the present time no practical results along the lines of bacteria have been obtained which our cheese manufacturers can make use of in the way of controlling with any accuracy this process of cheese ripening. Thus it will be seen that in this last dairy product bacteria play even a more important part than in any of the others. The food value of cheese is dependent upon the casein which is present. The market price, however, is controlled entirely by the flavour, and this flavour is a product of bacterial growth. Upon the action of bacteria, then, the cheese maker is absolutely dependent; and when our bacteriologists are able in the future to investigate this matter further, it seems to be at least possible that they may obtain some means of enabling the cheese maker to control the ripening accurately. Not only so, but recognising the great variety in the flavours of cheese, and recognising that different kinds of bacteria undoubtedly produce different kinds of decomposition products, it seems to be at least possible that a time will come when the cheese maker will be able to produce at-- will any particularly desired flavour in his cheese by the addition to it of particular species of bacteria, or particular mixtures of species of bacteria which have been discovered to produce the desired effects. CHAPTER IV. BACTERIA IN NATURAL PROCESSES.--AGRICULTURE.