78 RELATIONSHIPS OF THE COCCACE^ 



this respect, but they were insufficient to affect the aver- 

 ages for the larger groups. In regard to optimum 

 temperature a slight difference was manifest. In both 

 groups a large majority of the strains grew equally at 

 20 and 37 degrees. Among the cocci from the body, 

 however, 9 per cent grew better at 20 degrees and 

 27 per cent better at 37 degrees; of the saprophytic 

 cocci, 23 per cent grew better at 20 degrees and only 

 8 per cent at 37 degrees. In the proportion of gelatin 

 liquefiers the cocci from the body did not differ as a 

 whole from those found in saprophytic environments. In 

 the rate of action manifested by the liquefying forms 

 there was, however, a distinct difference. Of the cocci 

 from the body, 35 per cent failed to liquefy, 26 per cent 

 produced in 30 days a liquefaction less than 1.5 centi- 

 meters deep, and 39 per cent a liquefaction deeper than 

 1.5 centimeters; of the cocci from other sources, 39 per cent 

 failed to liquefy, 43 per cent produced a liquefaction less 

 than 1.5 centimeters deep, and only 18 per cent a lique- 

 faction deeper than 1.5 centimeters. 



One of the most striking differences between the para- 

 sitic and saprophytic forms appeared where it was least 

 expected, — in the respective chromogenic power of the 

 organisms. The common opinion among bacteriologists 

 has been that differences in pigment production were of 

 comparatively slight importance. The yellow and white 

 and red forms were indeed separated by Migula and 

 Chester; but no distinction was made by either author 



