su 



UAMPHASTID.K. 



RAMPHASTID*:. 



Ml 



trncture so peculiar to the stomachs of the true vegetable-feeder*. 

 (OM.lftu.ColL Chir.') 



The length of the tongue, one of the most remarkable among birds, 

 In a full grown Mutmiikatdti Toto was six inches. The poeterior 

 ridge, or backward-projecting process, wu broad and finely notched, 

 and situated about four linra from the glottin. Autenor to thin 

 proee**, Mr. Owen describe* the tongue at being *oft and minutely 

 papillow for the extent of four line*, and here he think* most probably 

 the sense of taate resides : the rest of the organ consist* of a trans- 

 parent horny lamina, flattened horizontally, and supported by the 

 anterior process of the os hyoides, which forms a ridge along the 

 middle of it* inferior surface. At about four inches from the 

 extremity of the horny lamina the margins become obliquely notched 

 ami these notches, becoming deeper and closer together towards the 

 extremity, occasion the bristled appearance on each side of the tongue : 

 theae bristles, were applied to the fooil in the cases of the captive 

 Toucan" above recorded. The coniua of the os hyoitles nre one inch 

 ami a half in length. 



Upper anrfaee of Tongue of Toucan. (Owen.) 



I, The (Tinted or feathered portion ; m, oriflce of larynx ; n, orifice of 

 pharynx ; o, eornna of the oa hyoides j f, trachea or windpipe j j, gullet. 



Professor Owen observe* that the osseous portions of the mandibles 

 of the Toucan are disposed in a manner adapted to combine with the 

 great bulk of those part* a due degree of strength and remarkable 

 lightlies*, and the bony structure is consequently of a most beautiful 

 and delicate kind. " The external parietes are extremely thin, espe- 

 cially in the upper beak : they are elastic and yield in a slight degree 

 to moderate pressure, but present considerable resistance if a force is 

 applied for the purpose of crushing the beak. At the points of the 

 mandibles, the outer walls are nearly a line in thickness ; at other 

 part* in the upper beak they are much thinner, varying from l-30th 

 to l-50th part of an inch, and in the lower beak are from l-20th to 

 1 30th part of an inch in thickness. On making a longitudinal section 

 of the upper mandible, its base is seen to include a conical cavity, 

 about two inches in length and one inch in diameter, with the apex 

 fit 



A, tNtlo* of the cranium and upper mandible of fetatj>*<ufi Tbw. , The 

 llaud structure of the beak ; *, th< catlty at the box ; c. branchea of the 

 * *"* ! *, *, et*rn*l oriacea of the aoatrlla ; e, oaaeotu parlctea of 

 Ml (iimpi ; f, oMtooa ubea protectlnc th* olfactory nerves ; t, pituitary 

 Mrtraa. tspoaed. and branch*, of the olfactory nerrea radlatini from It ; A, 

 Ireolar eanaU of the Internal ear j i, i, hembphera of the cere- 



. 



TtJeat Uitlm.l amion of the head. The same letter. Indicate the 

 t a. la the pnvimn aare. *, cerebellum ; I, the tonrue ; m, ilottla ; 



LUT^!? 1 * ' *' ~ ****** f > t " eh " ' ""P-M; 

 r. krvtai ^teai .nom . ^ .numlaUnr nurface of occipital bone ; I, 



UUon ; , alr-ctll interior to the orbit, from which the air 

 Mflbl* j , cancellated atractore of the lower Jaw. (Owen.) 



directed forward*. The walls of this cone consist of a most beautiful 

 ^.Intercepting insular angular spaces, varying in 

 iMn^.r from half a line to two line*. From the parieties of this 



, L S? ' ^ST!". 1 * oontil " e<1 * 0>e outward parietes of 

 the uaullUc, the fibre, which Immediately support the latter being 



almost invariably implanted at right angle* to the part in which they 

 are inserted. The whole of the mandible anterior to the ooue is 

 occupied with a similar network, the meshes of which are largest in 

 the centre of the beak, in consequence of the union which take* place 

 between different small fibres a* they pass from the circumference 

 inwards. It is remarkable that the principle of the cylinder is intro- 

 duced into this elaborate structure : the smallest of the supporting 

 pillars of the mandibles are seen to be hollow or tubular, when 

 examined with the microscope. The structure is the same in the 

 lower mandible, but the fibres composing the network arc in general 

 stronger than those of the upper mandible." (Owen.) 



Professor Owen states that the medullary membrane lining these cavi- 

 ties appears to have but a small degree of vascularity. Processes of the 

 membrane, accompanying vessel* and nerves, decussate the conical 

 cavity at the base of the beak. The principal nerves are two branches 

 of the fifth pair, which enter at the lower part of the conical cavity, 

 and diverge and ascend as they pass forward to the end of the bill, 

 giving off branches, which are distributed to the horny covering, and 

 supply it with insensibility. "The air," says Professor Owen, "U 

 admitted to the interior of the upper mandible from a cavity situated 

 anterior to the orbit, which communicates at its posterior part with 

 the air-cell continued into the orbit, and at its anterior part, with the 

 maxillary cavity. The nasal cavity is closed at every part, except at 

 its external and internal apertures, by the pituitary membrane, and 

 has no communication with the interior of the mandible." 



Smell. " The organ of smell is confined to the base of the upper 

 jaw. The canal, which is traversed by the air and odorous particles 

 in inspiration, forms a sigmoid curve in the vertical direction. The 

 external orifice is on precisely the same perpendicular line as the 

 internal one. It is situated at the posterior surface of the upper 

 mandible, where it is raised above the level of the cranium ; the 

 orifice is consequently directed backwards, secure from all injury that 

 might happen to it in the act of penetrating dense or interwoven 

 foliage. The olfactory canal is at first of almost a cylindrical form, 

 and about two lines in diameter. It passes forwards for about half 

 nu inch, receiving from the mesial aspect the projection of the first 

 spongy bone; it then bends downwards and backwards, and is dilated 

 to admit the projections of tho two other spongy bones : from this 

 point it descends vertically to the palate, at first contracted, and after- 

 wards dilating to form the internal or posterior orifice. The first or 

 outermost spongy bone is almost horizontal, and has its convexity 

 outwards. The second is nearly vertically placed, with its convexity 

 directed backwards: it terminates in a narrow point below. The 

 third or superior spongy bone makes a small projection towards the 

 mesial plane about the size of a pea. These spongy bones are formed 

 by inward projections of the inner and posterior osseous parietes of 

 the nasal passage : they are cellular, and air is continued into them 

 from the cranial diploe ; but the parietes of the nasal passage are 

 entire and smooth, and lined by a delicate pituitary membrane. The 

 inner table of the skull is continuous with the parieties of the nasal 

 cavity, by means of the bony canal which accompanies and protects 

 the olfactory nerves, and which represents, as it were, a single fora- 

 men of the cribriform plate of the Mammalia,, The communication 

 of the cavity of the cranium with that of the nose is thus similarly 

 formed, and is only obstructed in the recent state by the pituitary 

 membrane, on the posterior cul-de-sac of which the olfactory nerve 

 distributes its branches in a radiated manner. These branches were 

 confined, as Scarpa has observed in other birds, to the pituitary 

 membrane covering the septum narium and the superior spongy 

 bone." 



Hearing. " The external orifice of the meatus auditorius is situ- 

 ated about half an inch behind the lower boundary of the orbit. 

 The membrana tympani closes it so obliquely that its plane is 

 directed almost backwards ; ita anterior edge is consequently about 

 three lines from the external orifice, while its posterior margin is at 

 least six lines from the same point It is convex outwardly, as in 

 birds generally. The apparatus of the internal ear is easily exposed, 

 the semicircular canals being lodged in a delicate reticulation of the 

 dipliie of the cranium. These parts, with the ossiculum of commu- 

 nication and the cochlea, do not present any deviations from the 

 ordinary structure worthy of notice." 



Sight The sense of sight in tho Samphaitida appears to be 

 sufficiently well developed, but requires no special observation. 



Kespiratory and Circulating System. Mr. Owen found the trachea 

 narrow and simple in its structure, the rings somewhat flattened, and 

 decreasing in diameter towards the inferior extremity, from which n 

 single pair of muscle* passes off to the sternum. The length of tho 

 lower fourth of the tube, and the state of tension in the bronchia 

 are regulated by a pair of small muscles, which, arising from the 

 sides of the tracheal cartilages, are inserted into the bone of divari- 

 ntion at the extremity of the trachea ; this part of the tube is sub- 

 ected to variations in length, as is indicated by the tortuous character 

 of the recurrent nerves attached to the sides of the trachea in this 

 >art. The lungs, small in proportion, are of the usual form and 

 Ktrticture, and tho abdominal air-cells are also small. The heart is 

 more oblong than it is in birds generally; its apex, as it were, 

 .runcate ; and its length one inch. 



Urinary and Qenitnl System. The kidneys, composed of three 



