Some Bacterial Curiosities 49 



As a rule, bacteria are soon killed by bright 

 sunlight, and even in diffuse daylight many 

 pine and die. 



Among the most curious things which the 

 bacteriologist has to exhibit in his bacterial 

 conservatory is the color-forming species. It 

 is only when they are growing in masses, of 

 course, that enough color is formed to be 

 visible; but then one may see in the little 

 slimy masses which cover the surface of the 

 food or culture media in the tubes, every 

 color of the rainbow and many variations 

 in hue. Sometimes not only is the bacterial 

 mass itself brilliantly colored, but some of 

 the chemical substances which they form as 

 they grow permeate the gelatin and give it 

 a beautiful fluorescence, green or red. 



The writer was not long ago standing be- 

 side a supper-table, whose sole floral decora- 

 tion was a bunch of large, exquisitely tinted 

 chrysanthemums, when a friend remarked 

 upon the patience and skill which had been 

 required to develop this magnificent flower 

 by artificial selection from its simple and 

 homely ancestor, and queried in a quizzing 



