GEX. SCr.MBER. THE SPANISH MACKEREL. 193 



thing about ii is animated and exhilarating ; a brisk 

 breeze, a fair sk\% the boat in quick and constant 

 motion, all is calculated to interest and excite. He 

 who has experienced the glorious sensations of sail- 

 ing on the Western Ocean, a bright autumnal sky 

 above, a deep green lucid swell around, a steady 

 breeze, and as much of it as the hooker can stand 

 up to, ^vill estimate the exquisite enjoyment our 

 mominor's jNIackerel-fishinor afforded." 



(Sp. 44.) S. colias. The Spanish Mackerel. 

 S. pneumatophorus. Immediately after the Com- 

 mon Mackerel, M. M. Cuvier and Valenciennes de- 

 scribe, under the above names, two fishes which 

 are well known in the ]Mediterranean ; the one larger, 

 the other smaller than the preceding species. They, 

 moreover, differ from it in possessing an air-bladder, 

 which is truly remarkable, as thus stated by the 

 eminent authors just named, — one of the most curi- 

 ous facts in Ichthyology, and one of the most inex- 

 plicable in Comparative Anatomy, is, that fishes of 

 the same genus, and so closely resembling each 

 other in all the details of their organization that the 

 greatest attention is necessary in distinguishing 

 them, should the one be furnished with an air-blad- 

 der, and the other be deprived of it : "Why is it re- 

 quired in the one, and not in the other? What 

 cause operates in the production ©f this difference ? 

 Here are interesting problems for the consideration 

 of the theologian, the student of Nature and the 

 Providence of God. 



Corresponding with these Mediterranean fishes, 



