NOMENCLATURE AND CLASSIFICATIONS. 177 



enormous weight, since he depended not on mere assertion, but pointed out many 

 errors of fact and many flaws in the reasoning of his antagonists. 



To-day the majority of bacteriologists hold a sort of middle ground. Very few 

 are willing to accept the views of the old polymorphists, but there is a spirit of 

 rational inquiry abroad. We know that bacteria are much more responsive to 

 changed environment than was supposed by Koch and his followers in the eighties, 

 and we are prepared to believe anything respecting their origin and their poly- 

 morphism which can gain the suffrage of the great body of critical workers who 

 now cultivate this field, and who at once begin to investigate from all sides any new 

 and strange statement. Duplication of work, so called, is not waste of time.* If 

 sharp criticism abound, so much the better. In this way we shall gradually reach 

 a clearer understanding of these organisms. Meanwhile, let each one cultivate his 

 own little field as best he may, and, above all, let him be very sure of his facts before 

 he publishes. 



There can be no doubt that the same organism sometimes exists as a long fila- 

 ment in which no septa are visible and at other times as a short or nearly isodia- 

 metric rod, but we are not thereby compelled to consider the short form as a Micro- 

 coccus, i. e., as something very different from the long form. Physical conditions 

 probably have much to do with bringing about these differences. Respecting the 

 meaning of the branched forms, described by so many writers, the author is in doubt 

 and can only wait for more light. Several hypotheses are open : (i) The bacteria, 

 as now understood, are not a homogeneous group, but consist of many organisms 

 of dissimilar origin and differing morphologically, which will be gradually separated 

 out and put into their proper places, just as the Oosporas (Streptothrices) have 

 already been removed, leaving as /Tw-bacteria a genuine residuum of morphologically 

 similar forms ; (2) the bacteria do not any of them represent a natural group, but 

 are stages of various higher forms, just as certain cells, multiplying indefinitely in 

 yeast form, are now known to be conidial stages of the higher fungi (smuts, mncors) ; 



(3) the branched forms, which come mostly in old cultures, or in other crowded 

 conditions where the organisms are subject to the injurious action of their own 

 by-products (root-tubercles of L/eguminosse, lung-tubercles, etc.), are to be regarded 

 simply as involution or degeneration forms, and not higher stages of development ; 



(4) the branchings are incomplete longitudinal fissions favored by special chemical 

 or physical conditions. Time will show where the tnith lies. 



No harm will come to any one if all of these perplexing questions are not 

 settled definitely within his own generation. 



So far as can be judged from structure the bacteria appeared in early geologic 

 ages (in coprolites, decaying bones, tree-trunks, etc.) in forms closely resembling 

 those now existing, but we have very little definite information as to their origin. 

 Probably they are related to the lower algce and of as ancient origin. On rela- 

 tionship of the bacteria to Algae, Fungi, Flagellata, and Myxomycetes, see Migula's 

 remarks on the systematic position of the bacteria, in his "System," part I, page 237. 



*Karl Pearson has recently stated that 50 per cent of the scientific work of the igth century will 

 have to be junked as worthless. In bacteriology 75 per cent would be nearer the truth. 



