NATURAL HISTORY OF BRITISH SALMONID&. 139 



The female, regardless of the frequent absences of her lord 

 during his internecine contests, and probably satisfied with 

 the presence of the male parr, proceeds quietly with her opera- 

 tions by throwing herself at intervals of a few minutes, upon 

 her side, and whilst in this position, by a rapid action of the 

 tail, she digs a receptacle for her eggs, a portion of which 

 she on each occasion deposits, and, again turning on her side, 

 covers it up by a renewed action of the tail thus alter- 

 nately digging, depositing, and covering over until the whole 

 are laid. 



The adult fish after spawning are called ' spent ' or unclean 

 fish, or * kelts ; ' and at this time they are quite unfit for food 

 indeed almost poisonous and their capture is prohibited by 

 law. Lately spawned kelts may be recognised by their dark 

 unhealthy colour, lanky flaccid appearance, and by the enlarge- 

 ment of the vent. Their gills also are almost invariably found 

 to be infested by a species of white worm, the Lerncza salmonis 

 of Linnaeus, often improperly called a maggot, from which they 

 are released by contact with the salt water a similar release 

 from other parasites being obtained on passing to the fresh 

 water from the sea. 



For some time after spawning, however, they are in a very 

 weak and exhausted state, and have not energy for immediately 

 descending the river. Accordingly they usually drop down from 

 the spawning grounds, or * redds,' to the first quiet deep, there 

 remaining until their strength is recruited. They then con- 

 tinue falling back with the winter and spring floods, descending 

 from pool to pool, and avoiding as much as possible weirs and 

 rapid currents, until they reach the sea. Here they quickly 

 recover their condition, to ascend the rivers again (in at least 

 many cases) in the autumn or succeeding spring for the same 

 purpose as before, but almost always remaining some time in 

 the brackish water or tideway before making either decided 

 change. 



Within a period of five or six months after their return from 

 the salt water, it has been proved that at least a proportion of 



