MAKKET COLD-STORAGE CHICKENS. 



79 



Bacterial content of cold-storage chicken muscle. 



HISTOLOGICAL STUDIES. 

 TECHNIQUE/' 



A histological study was made of the muscle of the breast, using, 

 generally, the Pectdralis major, and in a number of cases the study 

 has been extended also to the muscle of the inner thigh and to the 

 walls of the abdominal cavity. 



The tissue was removed when making the bacteriological exami- 

 nation and fixed in alcohol, Zenker's fluid, and Orth's fluid. It was 

 found, for practical purposes, that the latter reagent was greatly to 

 be preferred, both for rapidity of fixing and the final cutting of 

 thin sections. Both the Zenker and the alcohol caused the fibers to 

 break and pull apart so that it is frequently an impossibility to 

 obtain sections which are trustworthy, especially from chickens 

 which have been in storage for a considerable length of time. 



The small pieces of tissue remained in Orth's fluid for from 18 to 

 24 hours. They were then washed in running water for another 24 

 hours, and run through alcohols of increasing strengths until finally 

 absolute alcohol was reached. From this they were put into anilin 

 oil until clear, which operation requires only a few minutes and 

 must be very carefully watched ; then into xylol until all the anilin 

 is extracted; next into a mixture of xylol and a paraffin melting at 

 52 C., which mixture is preferably kept at a temperature of about 

 37 C., and finally into a 52 C. melting point paraffin where, with 

 several changes, 24 hours "are needed for a complete infiltration. 



The histological preparations used in this study were made by E. Q. St. John. 



