BACTERIOLOGY OF REDDENED COD. 53 



Tomato broth. No development took place in the broth, nor in 

 broth to which gelatin was added. 



Pea broth. No development in this nor in pea gelatin. 



Cod-fish broth. No development in this nor in codfish gelatin 

 unless the inoculating culture were vigorous. 



ENZYMS. 



Bouillon to which 1 per cent of corn starch was added was inocu- 

 lated. After twelve days it was tested with Fehling solution for the 

 presence of sugar, but gave negative results. Beef gelatin which had 

 been liquefied by the bacillus had chloroform added to kill the organ- 

 isms. The liquid frothed at first, and was afterwards filtered. One 

 part was added to a 1 per cent starch paste and another to a tube of 

 gelatin. Thymol was added to prevent any growth. The paste was 

 tested for sugar and gave negative results. In twelve days there was 

 1 cc of the gelatin liquefied, and in thirty days 3 cc were liquefied. 

 It is evident that there is a proteolytic enzym formed by the bacillus, 

 but no diastase nor rennet, as shown by the behavior in the starch 

 medium and in milk. No tests were made for other enzyms. 



BROWN MOLD. 



Brown mold, as already stated, forms brown, freckle-like spots on 

 partially dried fish. It occurs usually on old fish, but may be found 

 on comparatively fresh fish also. Hake, haddock, and pollock are 

 the fish most affected by the fungus; it occurs to a lesser extent on 

 cod, cusk, etc. One is told sometimes that hake or pollock is the only 

 fish on which it occurs, which means that in that particular locality 

 the fish named is the one most subject to attack. Occasionally the 

 reason for the greater prevalence of the fungus on some one kind of 

 fish is that as the fish is cheap, it is not powdered. 



APPEARANCE OF MOLD. 

 v 



The fungus affects both sides of the fish, even covering the fins 

 and tail. On old fish it will sometimes form in lines, making odd 

 patterns, following irregularities on the surface, or it may develop 

 in such abundance as to form a layer of brown dust over the surface. 



The spots of the fungus when young are indistinguishable without 

 the aid of a lens, as they are the color of the fish, but as they become 

 older they turn brown, giving the fish the freckled appearance. The 

 brown spots, when magnified, often show a colorless center and brown 

 rim, in others the entire spot is brown. The brown rim is formed by 

 a comparatively large number of spores germinating in one spot, 

 sending out the hyphse from the outer side, and then forming conidio- 

 phores which turn brown as they mature. 



