THE KINDS OF MICRO-ORGANISMS IN MILK 



363 



The relation of Streptococcus lacticus to Str. pyogenes is a 

 problem of much interest and one that is not easily accounted for. 

 The genus streptococcus, if the term "genus" is permissible in 



Fig. 170. Rennet curds: a, Smooth curd without holes; 6, nearly smooth, 

 with many holes; c, uneven, with many holes; d, spongy; e, loose and broken 

 up. (Lohnis.) 



connection with this group of bacteria, has been the subject of 

 much study and controversy. To discuss this phase of the ques- 



Fig. 171. Fermentation tests of milk: a, Liquid milk; 6, jelly-like curd; c, 

 cheesy curd; d, gas formation; e, much gas formation. (Lohnis.) 



tion is not within the scope of our work, but a few words as to the 

 direct relation of Streptococcus lacticus to the genus streptococcus 

 may find space here. 



