102 LOCOMOTION OF FISHES. 



essential distinctions, provided any analogy exist 

 in elementary structure ; and that such an analogy 

 is maintained, in the case under consideration, is 

 unquestionable. 



The blade-bone or scapula of fishes in general, 

 is a somewhat broad and flat bone, attached some- 

 times to their spinal column — although without 

 forming a proper appendage to it, and sometimes 

 to the bones of the head ; at other times it is, as in 

 man, buried in the substance of the flesh, about 

 the shoulders, without any proper attachment to 

 either. With this are connected long spines, cross- 

 ing over the front of the neck, so as in general to 

 meet their fellows of the opposite side, and to 

 constitute arches below and behind the arches 

 formed by the lower jaw and lingual bones : and of 

 these, one corresponds to the collar-bone, or cla- 

 vicle, of the higher classes of animals; and the 

 other, which in fishes is called the coracoid bone, 

 to the merry- thought, or furcula, which is proper 

 to some reptiles and to birds. In this respect, 

 then, fishes are in advance of the mammiferous 

 animals, for the latter has no coracoid bone, or 

 furcula, but only the rudiments of it, in what is 

 called the coracoid process ; and many of them, for 

 example all those wdth hoofs, are destitute also of a 

 clavicle. But if fishes are before us in the develope- 

 ment of these bones, they are, in the same degree, 

 behind not only mammiferous animals, but reptiles 

 and birds also, in the next bone, or that corres- 

 ponding to the arm-bone, or humerus of man, 



