254 Modern Fishculture'in Fresh and Salt Water. 



an inch. The microscope shows them to be a cell con- 

 taining an egg with a living embryo. The egg is about 

 I -200 of an inch in diameter. As they are on the fins 

 they would seem to come from the outside. Those on 

 the sides of the fish have the egg apparently under the 

 scales and attached to the skin by a thread-like ap- 

 pendage which pulls out on removing the egg. Is this 

 a serious matter?" 



I have seen black bass, chubs, sunfish and other 

 species well sprinkled with these spots in early sum- 

 mer, and later in the season found worms in the flesh of 

 the fishes, but they seemed to do no harm, even to 

 people who ate the wormy fish. Somehow I connected 

 the spots and the worms together, but never tried to 

 work the thing out. I never saw them on trout. 



INTERNAL PARASITES. 



I took a tape-worm thirty-six inches long from a 

 shiner, whose extreme length was 4J inches. The fish 

 took my fly while trouting in the Adirondacks, and as 

 it was so unnaturally plump it was opened. 



White intestinal thread-worms are often present in 

 trout, and these worms pass from the intestines to the 

 body cavity, and even through the air bladder, after the 

 trout has been opened, but what they do before that 

 can't be seen. 



Many parasites of fishes, like tape-worms, do not 

 complete their existence in the fish, but their final host 

 is Some bird or mammal which eats the fish, just as the 

 tape-worm of the hare becomes complete in the fox; 

 that of the hog in man, etc. 



The trout of Yellowstone Lake are infested with 



