8 STUDIES OF POULTRY. 



culture, Bureau of Chemistry, as well as other matter which will 

 receive attention in its proper place. The investigations given in the 

 bulletin of the histology of cold-stored chicken muscle deal with 

 market birds only of which no history previous to storage was obtain- 

 able. The studies reported at the congress, however, were chiefly 

 based upon the examination of birds of known history, killed and 

 dressed and stored under known conditions, and examined at intervals 

 of one month for a period of a year. The muscle of birds which had 

 deteriorated at temperatures above freezing was also studied. A series 

 of characteristic post-mortem changes in structure was observed, 

 which differed from those prevailing in dead muscle at temperatures 

 above freezing and which were progressive. They were more pro- 

 nounced in the market fowls than in those of known history, as was 

 to be expected, since those from the market were certainly not treated 

 with the care before freezing that was given the experimental speci- 

 mens. The changes in the former were referable both to bacterial 

 growth (an invasion which occurred, doubtless, before storage) and 

 to enzym action both before and during storage. In the latter the 

 changes were due, apparently, to enzyms and to a coagulation of 

 protein caused probably by long contact with air. The changes were 

 evidenced by shrinkage and extreme brittleness of the fibers, by a 

 striking intensification of the cross markings and a glassy appearance 

 of the whole fiber, all of which might be referable to coagulation, and 

 by a disintegration of the fiber substance resulting in a structureless 

 mass, entangling connective tissue fibers and broken-down nuclei, and 

 staining a different color from the fibers which were intact hence, 

 indicating a change in the chemical constitution. 



The thawing of the specimens for histological examination was 

 carried on in cold air, and required at least twenty-four hours for 

 its accomplishment, hence there was time for the absorption of 

 exuded materials and a return to the normal if the fibers of the 

 chicken muscle were capable of doing so. Such histological changes 

 as were observed under the microscope were confirmed by coincident 

 chemical analyses of both market chickens (see Bulletin 115) and 

 chickens of known history stored for four months. In both publica- 

 tions the findings of the chemical analyses of both fresh and cold- 

 stored chickens are fully given. The study of the nitrogenous con- 

 stituents of the flesh includes the determination of the total amount 

 of nitrogen present, the amount of nitrogen soluble in cold water, the 

 quantity of such nitrogen which is coagulable by heat, the nitrogen 

 in the form of albumose and amino acid, and, by difference, the quan- 

 tity of peptone nitrogen and nitrogen insoluble in water. Light and 

 dark meat were analyzed separately. The fats were examined for the 



Proc. Int. Cong, of Ref . Ind., 1909, 2 : 248. 

 [Cir. 64] 



