168 FISH AS FA THERS. 



revolting creations. The hag not only lays a small num- 

 ber of comparatively large and well-stored eggs, but 

 also arranges for their success in life by supplying each 

 with a bundle of threads at either end, every such thread 

 terminating at last in a triple hook, like those with which 

 we are so familiar in the case of adhesive fruits and seeds, 

 like burrs or cleavers. By means of these barbed 

 processes, the eggs attach themselves to living fishes ; 

 and the young borer, as soon as he emerges from his 

 horny covering, makes his way at once into the body of 

 his unconscious host, whom he proceeds by slow degrees 

 to devour alive with relentless industry, from the intes- 

 tines outward. This beautiful provision of nature enables 

 the infant hag to start in life at once in very snug 

 quarters upon a ready-made fish preserve. I understand, 

 however, that cod-fish philosophers, actuated by purely 

 personal and selfish conceptions of utility, refuse to admit 

 the beauty or beneficence of this most satisfactory 

 arrangement for the borer species. 



Probably the best known of all fishes' eggs, however 

 (with the solitary exception of the sturgeon's, commonly 

 observed between brown bread and butter, under the 

 name of caviare), are the queer leathery purse-shaped ova 

 of the sharks, rays, skates, and dog-fishes. Everybody 

 has picked them up on the seashore, where children 

 know them as devil's purses and devil's wheelbarrows. 

 Most of these queer eggs are oblong and quadrangular, 

 with the four corners produced into a sort of handles or 

 streamers, often ending in long tendrils, and useful for 

 attaching them to corallines or seaweeds on the bed of 

 the ocean. But it is worth noticing that in colour the 



