MAINE SAfiDINE INDUSTRY. 25 



The results in Table 8 show that both ammonia and amines are 

 formed when Bacillus Walfischrauschbrand and Bacillus B are grown 

 in pure culture on fish media. Under the conditions which obtained 

 when these experiments were made, amines are formed in smaller 

 amounts than when the different lots of feed are decomposed at 

 incubator temperature. It would appear that a larger proportion of 

 amines are formed during the decomposition of the feed and the fish 

 under natural conditions. 



In the cultures of Bacillus Walfischrauschbrand and Bacillus B 

 used for the determination of ammonia and amines, positive tests for 

 both indol and skatol were obtained. These results confirm those 

 shown in Table 7 — that amm onia and amines are produced by these 

 organisms during the decomposition of the feed. 



Cause of Bell-y-Blown Fish. 



The fact that the bacteria found with the feed and in feedy fish 

 decompose fish tissue, elaborating the same end products of decom- 

 position as when the viscera and contents of herring decompose, 

 points clearly to the cause of the condition of the fish termed "belly 

 blown." It was shown (p. 86) that when the stomach and in- 

 testinal tract of the fish are empty, or practically so, no bacteria are 

 present. The bacteria associated with the feed are eliminated with 

 the digested feed or destroyed during the process of digestion. Only 

 when the stomach or intestines contain feed in an undigested or par- 

 tially digested condition are these bacteria found in abundance. 

 Their growth during these conditions, when the fish are dead, gives 

 rise to the products of decomposition. At certain times during the 

 prevalence of feed a large proportion of the fish on flakes just taken 

 from the steam boxes have been seen with the belly portions ruptured 

 in a manner suggesting an explosive bursting. Small amounts of gas 

 often were found lodged in some portion of the digestif e tract when the 

 gas-producing organiam was also present. When occurring in suffi- 

 ciently large amounts, the rapid expansion of this gas during the 

 steaming process may cause the rupturing of the partially digested 

 and weakened tissues suirounding the viscera. From this the term 

 "belly blown" undoubtedly originated. 



As the decomposition in the viscera and contents progresses 

 bacteria are carried into the surrounding tissues, which are rendered 

 soft by the alkaline materials, ammonia and amines. The thin belly 

 portion of the fish is disintegrated by the action of the bacteria, and as 

 decomposition progresses this portion of the fish gradually sloughs 

 away, producing the characteristic ragged appearance termed " belly 

 blown" (PL XVIII). The rapidity with which this condition is 

 brought about depends upon the extent to which the fish are gorged 

 with feed and the kind of bacteria accompanying the feed. Several 



