198 PHARMACEUTICAL BACTERIOLOGY 



The following recommendations are made: 



A. That the quality and purity of sterile evaporated milks be based 

 upon the following findings given in order of their importance: 



a. Diplobacilli, 



b. Diplococci, 



c. Streptococcus chains, 



d. Organic debris, other than casein or butter fat. 



It is recommended that the diplococcus and diplobacillus forms be 

 included in one and the same count, and that the count be stated as so 

 many pair per cc. Linear groupings of three or more coccus forms are to 

 be counted as streptococci, and the count is to be stated as so many chains 

 per cc. 



B. That sterile evaporated milk be declared below standard on the 

 following counts: 



100,000,000, or more, pair of diplococci and diplobacilli per cc., or 



300,000, or more, chains of streptococci per cc., or 



both; with or without the presence of body cells or any considerable amount of organic 

 debris, and with or without bacilli, tetracocci, or other associated microorganisms. 



C. That in case of non-sterile evaporated milk, or raw milk intended 

 for the canning and evaporating process, and in inadequately processed 

 canned milk, or milk in imperfectly sealed tins, or milk in unsuitable tins, 

 (tins with "Friction caps," for example), the direct microscopical ex- 

 amination be supplemented by the usual plating, tube, and fermenta- 

 tion tube culture methods. 



D. That under organic debris there should be included such organic 

 particles as are distinctly recognizable as other than sugar crystals, 

 casein granules or casein masses, or particles of butter fat. It may in- 

 clude the following substances: 



a. Vegetable tissue elements derived from field, soil, stable manure, or cattle feed. 



b. Dirt particles. 



c. Stringy shreds of albuminous matter. 



d. Variously colored (mostly reddish brown), irregular, amorphous, or somewhat 

 crystalline particles of resinoid character, probably largely of vegetable origin (decom- 

 position products). 



e. More or less disintegrated and not distinctly recognizable body cells (epithelium, 

 leucocytes, endothelial cells). 



These, and other particles of organic debris, are readily observable 

 under the low power of the compound microscope. In homogenized 

 milks that streptococcus chains are often well broken up, becoming largely 

 reduced to diplococcus forms and also to coccus forms. 



In the examination of full milks, fresh, evaporated, sweetened or 

 unsweetened, and inclusive of creams, ice creams, etc., a small high speed 



