XIV DEPARTMENT OF THE XAVAL SERVICE 



8 GEORGE V, A. 1918. 



XII. BACTERIOLOGY OF SWELLED CANNED SARDINES.— (Mr. Wilfrid 



Sadler, M.Sc, B.S.A.) 



After referring to the presence of micro-organisms in various foods, including 



mussels, clams, canned salmon, etc., the author refers to the canned method in the 



New Brunswick and Maine sardine canneries, which he visited. The filled and finished 



cans are sterilized in boiling water for 1^ to 2 hours. Scrupulous care is exercised in 



the final packing processes, and questionable cans are discarded or re-processed. 



Two main classes of bacteria were isolated; (1) gas-producers of eight types; (2) 

 non-gas-producers. 



No organisms were found in the cotton-seed oil used, but in the sea-water, herring- 

 intestines, etc., several strains of bacteria were discovered, but none producing gas 

 in carbo-hydrates. After a description of the seventeen or more media used, and the 

 methods adopted, Mr. Sadler describes the features of the swelled cans, the bulged con- 

 vex appearance, the escape and forcing out of oil or sauce between the soldered edges, 

 and a rattling sound when shaken. Gas is expelled on opening the can, and the odour 

 may be normal, or offensive. In the former case, doubtless spices and other ingredients 

 hide the odour of putrefaction. The contents may be soft, mingled with the oil and 

 maceated, in contrast to the firm non-macerated white appearance of the normal 

 contents. 



The elaborate cultures and tests in the laboratory are detailed by the author, and 

 summarized on pages 208 and 209. An experiment was made with normal cans from 

 the Chamcook factory, and the organisms, numbers 35, 37, a^d 64 were used for inocu- 

 lation. These organisms were, respectively: (1) a large coccus, not-motile, rod-like, 

 short, and thick; (2) rod-like, and three times as long as broad; (3) some ranging 

 from the coccus to short thick rods. In each case, typically swelled cans resulted. 



The source of the harmful micro-organisms remains to be discovered, and the 

 stage at which infection occurs; also effective prevention and the results of the effects, 

 by experimental inoculation, on laboratory animals. 



XIII. BACTERIAL DBSTRUCTION OE OOiPEPODS.— (Mr. Wilfrid Sa'dler, 



M.Sc, etc.) 



In some marine plankton, studied at the Atlantic station, in 191G, a number of 

 copepods, or small crustaceans, were observed by Professor Willey to be apparently 

 in process of destruction by bacteria. It was suggested to the author, by Dr. Willey, 

 that a study might be made of them. The copepods occur in the central cavity of 

 the first feelers or antennae. By the usual bacteriological methods, and by seven fish 

 concoctions, specially prepared, three different types of bacteria were isolated, fourteen 

 media being used in the investigation. The first type were short, rod-like, non-motile 

 organisms, non-spore-bearing, and without capsule; the second was of the same length, 

 but twice as broad, not much longer than broad, and similarly non-spore-bearing, 

 and apparently capsuleless, and lastly a third type, coccus, either in pairs or occurring 

 in masses in the form of Streptococci, non-spore bearing, and with capsule faintly 

 apparent. The first is probably B. neapolitanus, a sub-type of B. coli; the seconid, 

 rapidly motile to and fro, or on an axis, and a typical form of Para-G«ertner group; 

 and the third non-motile, though rotatory, and showing violent agitation, a variety 

 of liquefying Streptococcus gracilis^ namely Micrococcus zymogenes, and the last- 

 named culture probably causes the destruction of the copepods, and if this destruction 

 be extensive, its effective upon the minute food of young fishes, and a variety of other 

 important creatures in the sea, may be serious. No inoculations of healthy living - 

 copepods was possible in 1916. 



