MARKET COLD-STORAGE CHICKENS. 85 



ical appearance is more than explained by the structure of the tissue 

 as revealed under the microscope. 



Plates XII and XIII show the character of the intestine of a 

 fresh chicken and also of a chicken in cold storage for six months* 

 It will be observed that the muscular coats of the cold-stored chickens 

 have quite lost their characteristic structure. Apparently they con- 

 sist almost exclusively of the sheath of the fibers which, if they con- 

 tain muscle substance in any quantity, have it so altered chemically 

 that standard muscle-staining dyes do not affect it. What remains 

 of the individual fibers is a mass, loosely put together, which would 

 offer but little resistance to the migration of bacteria. 



So far as the cellular portions of the intestine are concerned they 

 are reduced to a minimum. Either the intestines are obliterated or 

 the cells are so dried and disintegrated that they are mere fragments. 

 Though the cell, as a whole, is in bad condition, the nucleus has 

 apparently offered greater resistance to the corroding action than 

 has the cytoplasm of the cell. 



GENERAL DISCUSSION. 



Bacteria and enzymes are most directly concerned in the question 

 of flesh decomposition, the effect of air, light, temperature, humidity, 

 and such conditions as are ordinarily considered responsible for altera- 

 tions in organized tissues being in reality factors influencing the 

 growth or activity of one or the other, or both, of the agencies stated. 

 The investigations of flesh decomposition which have been reported 

 have been conducted usually at room temperatures or at body heat. 

 Such studies at temperatures near 0° C. are almost entirely wanting, 

 probably because of the general idea that enzymic and bacterial 

 activities cease at or about zero. 



RESISTANCE OF BACTERIA TO LOW TEMPERATURES. 



The resistance of bacteria to low temperatures is well known, and 

 a number of investigators have subjected various species of organ- 

 isms to almost the lowest limit of modern cold. In 1884 Pictet and 

 Young a exposed B. anthracis, B. subtilis, Micrococcus leuteus, the 

 bacillus of symptomatic anthrax, beer yeasts, and smallpox vaccine 

 to temperatures varying from —70° C. to —130° C. and for periods 

 of from 20 to 108 hours. The bacteria proper were not destroyed; 

 the yeasts were intact microscopically but their functions were lost, 

 as was also the activity of the smallpox vaccine. Macfayden b 

 exposed a number of bacteria, both benign and pathogenic, to the 

 temperature of liquid air ( — 190° C), first for a period of 24 hours and 



a Compt. rend., Jan. to June, 1884, p. 747. 

 & Lancet, 1900, 1 [849]: 1130. 



