EXAMINATION OF MEATS 1 59 



rm of the Gaertner group of bacilli has been the infecting organ- 

 n. The Gaertner bacilli are large coli-typhoid types which 

 cupy a position intermediate between the chemically active 

 Ion group and the chemically inert typhoid group, and includes 

 enteritidis, B. typhi murium, B. suipestifer and B. paratyphosus 



Sausages and ham are the commonest sources of botulism, 

 om the anaerobic character of the bacillus it follows that poison- 

 g is rarely due to the eating of fresh sausage and pork. Invasion 

 meats by B. botulinus can take place only when the necessary 

 laerobic conditions exist, as for example when a ham is stored at 

 e bottom of the pickling vat and entirely covered by the pickling 

 lution, and in the interior of insufficiently cooked sausages and in 

 ored masses of sausage meats. 



The use of the compound microscope in the examination of 

 eats and meat preparations is still in its infancy. The work done 

 lows very clearly that with more experience very valuable in- 

 rmation can be obtained from the microscopical examination 

 garding the quality of meats of all kinds. It is highly probable 

 lat the microscope will show diagnostic differences in the muscu- 

 ture of different animals, thus making it possible to determine the 

 mrce of the meat. 



Considerable attention has already^been given to the micro- 

 popical study of fat crystals derived from the fats of different 

 secies of animals. So-called rancid fats or fats which have aged 

 Dnsiderably, even though they may not yet give evidence of ran- 

 idity to the unaided senses, will show more or less abundant 

 rystalline structure, arranged in clusters, which may be readily 

 een under the low power of the compound microscope. These 

 rystals are not apparent in fresh fats, but are generally more or less 

 bundantly present in canned meats and soup stocks containing 

 nimal products, in meat extracts and in other meat derivatives 

 aving fat admixtures. The presence of crystal clusters indicates 

 at decomposition and these are therefore an indication of the 

 uality of the meat product containing them. The degree of ran- 



