BACTERIOLOGY OF THE OYSTER. 23 



the action of the sea water. (2) The other and more important 

 function from the bacteriological point of view is that it serves as a 

 net for the entrapping of the food of the oyster which consists largely 

 of diatoms and algae, but is made up of all sorts of microscopic 

 particles, living or dead, organic or inorganic. As a consequence, the 

 bacteria as well as the other microscopic organisms get entangled in 

 this mucus. 



AVhen one opens an oj^ster and collects the juice, usually a great 

 many particles of mucus, some particles very large comparatively 

 speaking, are seen in the liquid. If one handles an oyster after 

 opening, it is found covered with a vicid, slimy substance which does 

 not wash off the hands easily If the bodies of the opened oysters 

 are allowed to stand for sometime there rises to the surface long 

 strings and flakes of this greenish yellow mucus. In shucking houses 

 it is customary to allow opened oysters to lie for some time in large 

 vats filled with water and with occasional stirring allow the mucus 

 to rise to the surface of the water and run over the edge, if running 

 water is used, or if not, it is skimmed off with a perforated dipper. 

 This mucus often collects in "ropes" two, three, or more inches long 

 and sometimes in large flakes the size of a half dollar. 



If one examines the liquor of the oyster he has just opened, it usually 

 contains a great number of particles of mucus, some large, some small. 

 If one collects the liquor in a bottle and allows it to stand over night 

 it will be found to have separated into two distinct layers, a heavy, 

 thick, viscous layer on the bottom and a clear, more limpid layer on 

 the top. The bottom layer is the mucus which has precipitated out. 

 Standard Methods of Water Analysis requires a water sample to be 

 shaken twenty-five times before the analysis commences, in order to 

 break up any clumps of bacteria. The second Progress Report of the 

 Committee on Standard Methods of Shellfish Examination^ recom- 

 mends that "bacterial counts shall be made of a composite sample 

 of each lot obtained by mixing the shell liquor of five oysters. Agar 

 shall be used for the culture medium and in general the procedure 

 shall be in accordance with the method recommended by the com- 

 mittee on Standard Methods of Water Analysis of the American 

 Public Health Association. " It can be inferred from the last sentence 

 of the quotation that it includes shaking the sample. In draining 

 the liquid from the oyster the water runs out of the shell not at a 

 single point, but over a considerable part of the edge of the shell. 



iJour. Am. Pub. Health, II, 1912, 34. 



