Bliss.] 6 [June 15, 



portion of the larger bone passes through an opening in the basi- 

 oceipital into the cavity of the cranium. These bones have received 

 the name of " the bones of Weber," in honor of Weber, who first 

 described them, and who homologized them with the bones of the 

 ear in mammals. Owen, in his "Anatomy of the Vertebrates " (Vol. 

 I, p. 344, et seq.), shows them to be a part of the auditory apparatus, 

 connecting the acoustic labyrinth with the air bladder. Owen says 

 Weber mistook the relation of analogy for one of homology when he 

 named them malleus, incus, and stapes. 1 



The posterior pair of parapophyses consist of small and thin trian 

 gular plates rising outward and upward, for a short distance, from 

 the centrum. 



In the first centrum of Doras niger the hasinapophyses exist as 

 downward prolongations of the centrum, forming a deep furrow in its 

 inferior surface. In the second centrum the furrow is closed for 

 nearly its entire length by the union of the haemapophyses. In the 

 third and fourth centrums the haemapophyses form a furrow, as in the 

 first, which exists also in the two following centrums, though much 

 less distinctly marked. Hence the haemapophyses form a continuous 

 furrow on the under surface of the coalesced centrums, but unite in 

 the second so as to form a tube. 



The second centrum has not only two pairs of parapophyses, but 

 also two neural spines. The first neural spine of this centrum (the 

 second spine of the vertebral column) starts from the anterior por- 

 tion of the centrum, above the anterior parapophyses, and rising 

 upward and backward, meets the downward prolongation of the 

 second intern eural spine, to which it is firmly united. This inter- 

 neural spine has two outstanding lateral wings ; these expand supe- 

 riorly, and uniting form a single broad and arched dermal plate, 



1 This view of "Weber was strongly opposed by Geoffroy St. Hilaire, who consid- 

 ered these bones to be the modified ribs of the first, second and third vertebras. 

 Meckel was inclined to agree with Weber in considering them the homologues of 

 the bones of the ear. Saagmans Mulder described the bones as a part of the audi- 

 tory apparatus ; believing the air bladder to be identical with the tympanic mem- 

 brane. Later, however, he came to the conclusion that the bones considered by 

 "Weber as malleus and incus, Avere but ribs ; and the stapes as transverse apophyses 

 of the first vertebra. Brechet believed them to belong to the auditory apparatus, 

 and Valenciennes considered them as special bones. Baudelot reviews the subject 

 at some length in " Comptes Rendus " for 1868, pp. 330-334 and comes to the conclu 

 sion that these bones represent the superior arches of the first and second vertebras 

 the inferior arch of the third, and the os intercrural parted in two. 



