SHARKS. 303 



weaker and more easily ruptured than any other 

 part ; a provision for the easy exclusion of the 

 animal, which takes place before the entire 

 absorption of the vitellus or yolk of the eg^, the 

 remainder being attached to the body of the 

 young fish, enclosed in a capsule, which for a 

 while it carries about. The position of the ani- 

 mal, while within the egg, is with the head 

 doubled back towards the tail, one very un- 

 favourable for the process of breathing by in- 

 ternal gills, and hence there is an interesting 

 provision made to meet the emergency. On each 

 side a filament of the substance of the gills 

 projects from the gill-opening, containing vessels 

 in which the blood is exposed to the action of 

 the water. These processes are gradually ab- 

 sorbed after the fish is excluded, until which the 

 internal gills are scarcely capable of respiration. 

 How curious an analogy we here discover with 

 the Frogs and Newts among the Reptiles ; and 

 how impressively do we learn the Divine benevo- 

 lence, when we find that the object of so much 

 contrivance and care is the dreaded and hated 

 Shark! 



In some species the horny capsules in which 

 the young are enclosed at birth are destitute of 

 the filamentous prolongations of the angles ; in 

 some they have but two projecting points, one 

 end being rounded ; wliile other species, as 

 the Penny Dog {Galeus vulgaris), and Smooth 

 Hound, {Mustelus Icevis), of our own shores, bring 

 forth their young alive and fully formed, without 

 any capsule or covering at all. 



A hundred and fourteen species are reckoned 

 by Prince Bonaparte to belong to this Family ; 



