2IO 



POPULAR SCIENCE MONTHLY. 



As spawning progresses, both sexes rapidly become emaciated. 

 Their fins become frayed and worn, especially the caudal fin of the 

 female, which is frequently entirely worn off. Fungus attacks the 

 skin in various places, especially the top of the head and the fins, and 

 it frequently destroys one or both eyes. The gills are nearly always 



Alimentary Canal of a Salmon taken 

 in Monterey Bay. 



Alimentary Canal of a Salmon aftek 

 Spawning, taken at Battle Creek 

 Fishery 



attacked by fungus and parasitic Copepods, and half or even three 

 fourths of the gill filaments are sometimes thus destroyed. The skin 

 is worn off in many places, such as the side of the tail, the projecting 

 edges of the jaws and fins, and the snout of the male. They have 

 eaten nothing since leaving the ocean, and the alimentary canal has 



Male and Female after Spawning. 



long since shriveled up until the stomach is scarcely one tenth its 

 normal size; a catarrhal desquamation takes place all along the 

 digestive tract, but especially posterior to the stomach, which portion 

 is frequently filled with tapeworms. At least two other kinds of 



