THE VITAL PHENOMENA OF BACTERIA. 63 



chemical groups. Some of these pigments arise 

 from the decomposition of proteid bodies and 

 themselves manifest, in part at least, proteid 

 characters. Hoffa and Enoch succeeded in ex- 

 tracting from fluorescing cultures a proteid-like 

 body which in solution gave a fine green fluor- 

 escence. Other pigments, as for instance, the 

 familiar red pigment with green fluorescence 

 manufactured by the " miracle germ " are re- 

 lated chemically to the aniline dyes. Hueppe 

 has shown that the magnificent ultramarine 

 blue pigment of blue milk is formed out of 

 proteid substance and also out of ammonia and 

 a substance which is formed both analytically 

 from sugar and synthetically from milk-sugar. 

 Zopf and Overbeck, 1 finally, have ascertained 

 that some bacterial pigments belongs to the 

 lipochromes or fatty pigments ; according to 

 Biitschli perhaps the bacterio-purpurin of Beg- 

 giatoa also belongs here. 



Investigations by Forster 2 and Fischer 3 

 have shown that bacteria exist in the ocean 

 and in the soil which can multiply at o C. 

 They observed, for example, that M. phos- 

 phor escens grew upon fish and evoked visible 

 luminosity at this temperature in 68 days. 

 Zopf observed a species found in surface water 



iNov. Act d. Kais. Leop.-Carol Akad. LV., 1891, No. 7. 



2 Centralbl. f. Bakt. II., 1887, XII., 1892. 



3 Centralbl. f. Bakt. IV., 1888. 



