OSSICIILA AUDITTJS IK THE HIGHER MAMMALIA. 
903 
portion of the Meckelian cartilage. The incus and stapes they consider to arise 
independently, but in what manner they do not make clear; they mention that the 
stapes is a perforated and not a solid ball of cartilage at its first appearance, as had 
been described by Reichert. Brtjch (8) describes the mandibular cartilage, with the 
malleus and the incus, as forming one continuous strip of cartilage ; but he also 
mentions that he has seen the malleus and incus take their origin in a special cartilage 
which soon united with the mandibular one. 
The stapes appears at the upper end of the hyoidean cartilage as a somewhat square¬ 
shaped cartilage, whether continuous with it or not he does not state ; it is the latest 
of the ossicula to appear. 
Huxley (9) in his earlier writings accepted the views advocated by Reichert, but 
at a later period he has advanced views of his own based upon comparative anatomical 
work, and more especially on the condition of parts found in “sphenodon punctatum.” 
He describes the malleus as forming the proximal extremity of the mandibular cartilage. 
He divides the hyoidean into a part above and a part below the stapes; the former 
becomes the incus or supra stapedial, which is connected by a distinct ossification—the 
orbicular bone—to the stapes; the latter becomes the infra-stapedial or stylo-hyal of 
the Mammalia, which may be connected to the supra-stapedial either by means of the 
stapedius muscle, which passes to the orbicular bone, or by means of a ligament which 
passes to the short crus of the incus. 
He mentions also that in many Fishes and Amphibia the proximal ends of the two 
cartilages are united into a single plate. 
Parker (10) describes the malleus also as the proximal end of the mandibular car¬ 
tilage, the apex of which grows downwards over the first visceral cleft and forms the 
manubrium mallei, the shoulder of the bend forming the head with its articular 
surface; the hyoidean cartilage undergoes segmentation ; the upper part becomes the 
incus, the apex of the bar growing downwards forms an attachment by its capitulum 
(which becomes the orbicular bone) with the stapes; the shoulder of the bend becomes 
the body and articular surface of the incus, which unites with the corresponding part of 
the mandibular cartilage. From the shoulder or bend a little boss grows backwards 
which becomes the short process of the incus. The rest of the cartilage is carried 
backwards and downwards, but is connected to the previously described part by a 
ligament, the inter-hyal, in which a nodule of cartilage appears, one end of which 
becomes attached to the head of the stapes, the other is buried in the substance of the 
stapedius muscle. The head of that part of the cartilage carried downwards is bifur¬ 
cated ; the outer division becomes attached to the tegmen tympani, the inner to the ear 
sac immediately in front of the exit of the cranial nerve. The stapes is derived from 
the median of three projections, which appear on the external surface of the wall of the 
labyrinth ; it frees itself from the wall, leaving a gap, the future fenestra ovalis, which 
is closed by the separated nodule ; externally, the nodule is covered by delicate indif- 
MDCCCLXXXII. 
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