190 Profs. P. F. Frankland and Marshall Ward. 



is at least not impossible that the forms described as Bacterium 

 sulphuratum, Merismopedia littoralis, M. Beitenbachii, Monas vinosa, 

 M. Warmingii, M. erubescens, M. Okenii, M. gracilis, Spirillum viola- 

 ceum, Bhabdomonas rosea, &c, by different observers are merely 

 form -phases of Lankester's species.* So long as investigators are 

 content with recording and naming forms without cultivating them, 

 such difficulties as the above will increase, and most of the trouble 

 met with in the literature of bacteriology — so far as their morphology 

 is concerned — is traceable to this error. 



A still longer list of bacteria are recorded as having been occasion- 

 ally met with in various waters, though most of them are not 

 characteristic of such habitats. Among these are : Bacillus subtilis 

 (Ehrenb.), Proteus vulgaris (Hauser), Bacillus anthracis (Cohn), 

 Spirillum cholerm-asiaticce (Koch), Bacillus typhosus (Eberth-Gaffky), 

 B. aquatilis sulcatus (Weichselbaum), B. dysentericus (Aradas), B. 

 thermophilus (Miqu.), Micrococcus agilis (Ali-Cohen), and others. f 



Here, again, it must be remarked that many of the forms are un- 

 satisfactory as regards their autonomy — e.g., Proteus vulgaris, Micro- 

 coccus agilis — and that we find no record of the authority for B. dysen- 

 tericus, referred to by Aradas. 



We have decided to omit detailed references to numerous other 

 forms, recorded as occurring in water, but under names which 

 convey no specific meaning, though some of them are not necessarily 

 bad records ; others, again, are referred to by the authors in such a 

 loose way that it is impossible to accept them until they have undergone 

 revision. Thus, Eisenberg refers torodlets which lie dubs " Violetter- 

 bacillus," " Qasbildender -bacillus" " Verflussigender-bacillus" &c.,J 

 and Perdrix, in an excellent paper§ in other respects, speaks of 

 Bacille amylozyme, a form met with in the rivers of Paris. So far as 

 it has been possible we have given these in the lists in Appendix B ; 

 but we desire to point out that the labour of hunting up the synonyms 

 recorded for these and other imperfectly named forms is very great, 

 and that, therefore, omissions may possibly be discovered with regard 

 to some of them. 



Among such forms we may also mention Bacillus arbor escens, B. 

 liquidus, B. vermicularis, B. nubilus, B. ramosus, B. aurantiacus, B. 

 viscosus, described by one of us;|| also Meade Bolton's Micrococcus 



* Winogradsky denies the accuracy of Zopf's views on this matter, however (see 

 'Beitrage z. Morph. u. Phys. der Bakt.,' 1888). 



f See Appendix B for a complete list of these and all other bacteria known to 

 occur in various waters. 



X ' Bakteriologische Diagnostik,' Berlin, 1886. Some of these forms have since 

 received definite names, adopted by Eisenberg in the edition of 1891. (See Ap- 

 pendix B.) 



§ 'Ann. de l'lnst. Pasteur.' vol. 5, 1891, pp. 286—311. 



{| Grace C. and Percy F. Frankland, 1 Zeitschr. f. Hygiene,' vol. 6, 1889, p. 373. 



