842 REPORT— 1897. 



As matter of fact, the introduction and gradual specialisation of Koch's methods 

 of rapid isolation of colonies encourag-ed the very dangers they were primarily 

 intended to avoid. It was soon discovered that pure cultures could he obtained 

 so readily that the characteristic differences of the colonies in the mass could 

 presumably be made use of for diagnostic purposes, and a school of bacteriologists 

 arose who no longer thought it necessary to patiently follow the behaviour of the 

 single spore or bacillus under the microscope, but regarded it as sufficient to 

 describe the form, colour, markings, and physiological changes of the bacterial 

 colonies themselves on and in different media, and were content to remove speci- 

 mens occasionally, dry and stain them, and describe their forms and sizes as they 

 appeared under these conditions. 



To the botanist, and from the points of view of scientific morphology, this 

 mode of procedure may be compared to what would happen if we were to frame 

 our notions of species of oak or beech according to their behaviour in pure forests, 

 or of a grass or clover according to the appearance of the fields and prairies com- 

 posed more or less entirely of it, or — and this is a more apt comparison, because 

 we can obtain colonies as pure as those of the bacteriologist — of a mould-fungus 

 according to the shape, size, and colour, &c., of the patches which grow on bread, 

 jam, gelatine, and so forth. 



Now it is obvious that this is abandoning the methods of morphology, and 

 the consequence has been that two schools of descriptive bacteriologists are 

 working along different lines, and the 'species' of the one — the test-tube school — • 

 cannot be compared with those of the other, the advocates of continuous culture 

 from the spore. 



The difficulty of isolating a bacterium and tracing its whole life-history under 

 the microscope is so great, that the happy pioneers into the fascinating region 

 opened up by the test-tube methods may certainly claim considerable sympathy 

 in their cry that they cannot wait. Of course they cannot wait ; no amount of 

 argument will prevent the continual description of new test-tube ' species,' and 

 all we can do is to go on building up the edifice already founded by the botanists 

 Cohn, Brefeld, De Bary, Van Tieghem, Zopf, Prazmowski, Beyerinck, Fischer, 

 and others who have made special studies of bacteria. 



The objection that such work is slow and difficult has no more weight here 

 than in any other department of science, and in any case the test-tube school is 

 already in the plight of being frequently unable to recognise its own ' species,' 

 as I have convinced myself by a long-continued series of cultures with the object 

 of naming common bacteria. 



I wish to guard myself against misconstruction in one particular here. It is 

 not insinuated that the test-tube methods and results are of no value. Far from it ; 

 a vast amount of preliminary information is obtained by it; but I would insist upon 

 the discouragement of all attempts to make ' species ' without microscopic culture ; 

 and continuous observation of the development as far as it can be traced. 



The close connection between bacteriology and medicine has been mainly 

 responsible for the present condition of aflairs ; but it is high time we recognised 

 that bacteriology only touches animal pathology at a few points, and that the 

 public learn that, so far from bacteria being synonymous with disease germs, the 

 majority of these organisms appear to be beneficial rather than inimical to man. 

 There is not time to attempt even a brief description of all the ' useful fermenta- 

 tions ' due to bacteria, but the following cases will point the conviction that 

 a school of bacteriology, which has nothing to do with medical questions, but 

 investigates problems raised by the forester, agriculturist, and gardener, the 

 dairyman, brewer, dyer, and tanner, &c., will yet be established in England 

 in connection with one or other of ottr great botanical centres. 



There are many industrial processes which depend more or less for their success 

 on bacterial fermentations. The subject is young, but the little that has been 

 discovered makes it imperative that we should go on, for not only are the results of 

 immense importance to science, but they open up vistas of practical application, 

 which are already being taken advantage of in commerce, and we may be sure that 

 every economic application of such knowledge will give the people employing it an 



