240 LANTHEEN JACK SPRATS. 



many tliousand tons are annually disposed of in tins 

 manner." The length of the sprat is from 5in. to Gin. 



Its food is similar to that of the herring. In my 

 " Cmiosities of Natural History" I have thus de- 

 scribed the sprat's mouth : "It looks a little tiny 

 moutlv not large enough to admit a pin's head ; but 

 just push down the lower jaw, and what do you see ? 

 Why, one of the most beautiful insect nets it is possible 

 to conceive. A net into which you can get the top of your 

 little finger, and of necessity terribly destructive among 

 the minute sea creatures which the sprat feeds on — those 

 pretty little animals which cause the sea to be luminous 

 at night, forming, doubtless, part of the bill of fare." 



As the salmon has parasites on his scales, the Ler- 

 neonema, and in his gills, so we find that the sprat has 

 a parasite called LerncBa spratti. 



These parasites fix themselves on to the eye of the 

 fish and there anchor themselves, a portion of the body, 

 and the ovaries, which are like two long green threads 

 hanging loose to the length of 2^in. They sometimes 

 enter the body of the fish near the dorsal fin, and pierce 

 to the depth of ^in., the head coming down from the 

 back of the sprat, through the flesh, nearly to the belly. 

 They are of a beautiful green colour. The fishermen 

 call them " Lantern Jacks." The story is that the fish 

 which carries these "Lantern Jacks" is the pilot fish 

 of the shoal, and that the lantern is luminous at night, 

 and the shoal steers itself on the course indicated by 

 the bearer of the " Lantern Jack." 



There is confusion in the minds of those concerned 

 as regards names. Some designate a sprat a " garvie ;" 

 some call a young herring a " garvie ; " some call both 

 si)rats and herrings alike " garvies." 



* See " Deep Sea Fisheries Report, 1879." 



