Fio. 57. N'ibrio Rugula, with Plagella. Agar culture. Stained 

 with Orcein solution. X 1000. 



FIG. 58.* Spirillum Undula, with Flagella. X 1000. 

 I am indebted to Herr Hansel, 29 Dorothean Strasse, Berlin, for this specimen. 



[T ; Bou-hill, F.P.C.l\S., Photo., Edinburgh, 1898. 



