MAINE SARDINE INDUSTRY. 



23 



volatile alkaline material in a catch of plankton, which consisted 

 almost entirely of diatoms, is also given. The rate of decomposition 

 of fresh-water herring is included for the sake of comparison with the 

 rate of decomposition of the feed alone. 



In each case as many determinations were made as were possible 

 with the amount of material at hand, which was not often large 

 because of the difficulty of obtaining any kind of feed unless the 

 water was very quiet. The amount of total volatile nitrogen found 

 before incubation was so small that it seemed unnecessary to deter- 

 mine amine nitrogen. 



Table 7. — Ammonia and amines per 100 grams in feed of sea herring. 





When taken. 



Held in incubator. 



Feed.i 



24 hours. 



48 hours. 



72 hours. 





Total. 



Am- 

 mo- 

 nia. 



Am- 

 ines. 



Total. 



Am- 

 mo- 

 nia. 



Am- 

 ines. 



Total. 



Am- 

 mo- 

 nia. 



Am- 

 ines. 



Total. 



Am- 

 mo- 

 nia. 



Am- 

 ines. 



Plankton from Woods Hole, 

 Mass.. kept at 30° C. 

 (chiefly diatoms) 



Mg. 

 2.82 



6.04 



3.94 



Mg. 



Mg. 



Mg. 



Mg. 



Mg. 



Mg. 



Mg. 



Mg. 



Mg. 

 4.14 



402.2 



Mg. 



Mg. 



Plankton from St. Croix 

 River off Campobello Is- 

 land (chiefly copepods)... 



Copepods from east and 

 south of Campobello Is- 

 land 



























272.4 

 216.6 

 191.7 



206.2 

 153.8 

 143.4 



66 2 

 62.8 

 48.3 



468.2 



375.1 



93.1 







Copepods from shallow 

 water east of Grand 













Copepods from north end 

 of Grand Manan in very 



9.50 

 1.98 

 3.95 







296.8 



260.9 



35.9 









Schizopods from Wilson's 

 Beach Island, off Campo- 

 bello 







822.9 

 1009.2 



602.3 

 832.6 



220.6 



Schizopods from Wilson's 

 Beach Island, off Campo- 

 bello 







220.4 



88.2 



132.2 



787.6 



573. 7 



213.9 



176.6 



Feed taken from belly- 

 blown fish at wharf, East- 



37.7 



17 1 



20.6 





Fresh-water herring from 

 Taunton River, Taunton, 



9. 94 - - 



127.0 



111.6 



15.4 









888.3 



812.6 



75.7 





















1 Samples were kept at incubator temperature (37.5° C). 



Both ammonia and amines in very large quantities were found in 

 the decomposing feed, schizopods and copepods. When allowed to 

 spoil under these conditions and to the extent that took place during 

 a period of from 48 to 72 hours, ammonia was found in much larger 

 amounts than amines. From the limited number of determinations 

 it was possible to make it was apparent that little difference, if any, 

 exists in the rate of decomposition or in materials formed between 

 copepods and schizopods. Considering the similarity of composi- 

 tion of the two forms, it is quite probable that no difference in 

 degree or kind of decomposition would be found. The examination 

 of the feed taken from the viscera of belly-blown fish gave results 



