68 



NA TURE 



\^Nov. 26, 1874 



The casual visitor must also enter a protest against the unclean 

 state of the cages of the Raptorial Birds, which are s|ilashed all 

 over with ordure, offensive to the sightseer m appearance and 

 smell, and injurious to the health and plumage of thejbirds 

 themselves. , , r i- 



The drainage of the Zoological Gardens is also so defective 

 as to be verging on a public nuisance to the inhabitants ol the 

 banks of the Regent's Canr.1, so that some means must soon be 

 taken for the better disposal of the sewage. ^ 



If facilities do not exist for extending the area of the Regent s 

 Paik Gardens, from want of power to acquire more ground, then 

 it should become a serious question whether or not a supplemen- 

 tary Garden might be obtained in the suburbs further off. It 

 could scarcely be expected that the subscribers would relinquish 

 the reteniion of the present position, on account of its advaii- 

 tageous situation in the town for the access of visitors. It is 

 quite possible visitors might be satisfied with much/t-?i'iT animals 

 to see, especially of those unattractive in appearance and habits, 

 and it could easily be decreed that all these might be>entto 

 another garden for scientific purposes alone. 



Further, the second garden might be appropriated for breeding 

 purposes, and change of air and locality for the usual inhabitants 

 of the old enclosures and dens and cages, when the latter were 

 required to be repaired or disinfected ; and finally, it might be 

 used as 3. sanatorium for the sick, and an asylum for the decrepid 

 and disabled members of the stock, when their further exhibition 

 in public is no longer desirable. 



'I'he great prevalence of tubercular and scrofulous diseases 

 reported to exist amongst the animals should also be cited 

 as indicative of a necessity for increased space and ventilation 

 being required in the gardens, and it is much to be desired that 

 some statistics of this class of disorders should be compiled and 

 published for general information, giving details of its greater or 

 less frequency in special classes of quadnipeds, birds, reptiles, 

 and fishes. Viator 



It has often occurred to me that the ofticers in charge of our 

 Zoological Gardens enjoy exceptional opportunities of ascertaining 

 experimentally the limiis of the intellectual and educational capa- 

 hiliiies of the animals under their charge, but I am not aware of 

 the existence ot any systematic effort to realise the harvest of 

 v.iluable and interesting inlormation that lies here waiting to be 

 jjathered. Is not this an object woithy of the attention of the 

 Zoological Society ? 



Nov. 17 C. Traill 



NOTE ON THE DEVELOPMENT OF THE 

 COLUMELLA AURIS IN THE AMPHIBIA* 



IN his paper " On the Structure and Development of 

 the Skull of the Common Frog" (Phil. Trans. 1871), 

 Mr. Parker states that, in the fourth stage of the tad- 

 pole,f " the hyoid ax^h has made its second great mor- 

 pliological change ; it has coalesced with the mandibular 

 pier in front and with the auditory capsule above (Plate V. 

 Figs. I — 4, and Plate VI. Fig. 8, s.h.m., i.li.in) The 

 Ujjper part, or supra-hyomandibular [s.h.m.), is attached 

 t J the auditory sac mucti lower down and more outward 

 than the top of the arch in front. . . . This upper distinct 

 part is small ; it answers to only the upper part of the 

 Teleostean hyomandibular ; there is a broad sub-bifid 

 upper head answering to the two ichthyic condyles, then 

 a narrow neck, and then behind and below an ' opercular 

 process ' [op.p.) Below this the two arches are fused 

 iDgether ; but the hyoid part is demonstrated just above 

 the commencement of the lower third, by the lunate fossa 

 lor the ' styloid condyle' (Plate V. Figs. 2 and 4, st.h.) " 

 (Pi>- 154, 155)- 



In the sixth stage : — " The supra-hyomandibular (Fig. 3, 

 s./iiii.) has become a free plate of cartilage of a tnfohate 

 form" (p. 164). 



In the seventh stage: — "The 'supra-hyomandibular' 

 losing all relation to the hyoid arch, becomes now part of 



* Read at the meeting of the British Association at Belfast, August 25, 

 1874, by Prof. T. H. Huxley, KK.S. 



t Tnat is, when there is a branchial aperture only on the left side, and the 

 hind hmLis are rudimentary or very small. 



the middle ear. . . . The essential element of the middle 

 ear, the stapes {st.), was seen in 'the fourth stage ; the 

 condyles and opercular process of the hyomandibular are 

 now being prepared to form an osseo-cartilaginous chain 

 from the ' membrana tympani' to the stapes. Under 

 these conditions a new nomenclature will be required ; 

 and this will be made to depend upon the stapedial rela- 

 tionship of the chain, notwithstanding its different mor- 

 phological origin. 



" I shall now call the lobes of this trifoliate plate of 

 cartilage as follows — namely, the antero-superior ' supra- 

 stapedial,' the postero-superior ' medio-stapedial,' and the 

 freed opercular process ' extra-stapedial ' [s.st., 7ii.st., e.st.) 



" The stapes [st.) sends no stalk forwards to meet the 

 new elements, but they grow towards it ; this will be seen 

 in the ne.xt stage" (pp. 169, 170). 



As the question of the origin of the columella aiiris in 

 the Vcrtebfata is one of considerable morphological im- 

 portance, I have devoted a good deal of time, during the 

 past summer, to the investigation of the development of 

 this structure in the frog, and it is perhaps some evidence 

 of the difficulty of the inquiry, that my conclusions do 

 not accord with those enunciated by Mr. Parker, in the 

 very excellent and laborious memoir which I have cited. 



I find, in the first place, that there is no coalescence of 

 the mandibular with the hyoidean arch, the latter merely 

 becoming articulated with the former. 



Secondly, Mr. Parker's " supra-hyomandibular " is 

 simply an outgrowth of the mandibular arch from that 

 elbow or angle which it makes, when the pedicle by which 

 it is attached to the trabecula passes into the downwardly 

 and forwardly inclined suspensorial portion of the arch. 

 This outgrowth attaches itself to the periotic capsule, and, 

 coalescing with it, becomes the otic piocc'ss, or "superior 

 crus of the suspcnsorium " of the adult frog. 



The hyoid arch, seen in the fourth stage, elongates, and 

 its proximal end attaches itself to the periotic capsule, in 

 front of the fenestra ovalis and close to the pedicle of the 

 suspensorium, which position it retains throughout life. 



The columella auns arises as an outgrowth of a car- 

 tilaginous nodule, which appears .at the anterior and 

 superior part of the fenestra ovalis, in front of and above 

 the stapes, but in immediate contact with it. It is to be 

 found in frogs and toads which have just lost their tails, 

 in which the gape does not extend farther back than the 

 posterior margin of the eye, and which have no tympanic ' 

 cavity, as a short and slender rod which projects but very 

 slightly bsyond the level of the stapes, its free end being 

 continued into fibrous tissue, which runs towards the sus- 

 pensorium, beneath the portio dura, and represents the 

 suspensorio-stapedial ligament of the Uroacla. 



This rod elongates, and its anterior or free end is carried 

 outwards, in proportion as the tympano-eustachian passage 

 is developed. At the same time, the free end becomes elon- 

 gated at right angles to the direction of the rod, and gives 

 rise to the " extra-stapedial " portion, which is imbedded 

 in the membrana tympani. Ossification takes place 

 around the periphery of the middle of the rod ; thus the 

 medio-stapedial is produced. The inner portion becomes 

 the rounded, or pestle-shaped, supra-stapedial, but retains 

 its primitive place and connections, whence we find it in 

 the adult articulated in a fossa in that part of the periotic 

 capsule which forms the front boundary of the fenestra 

 ovalis, but in close contact with the stapes. 



The columella auris of the frog, therefore, is certainly 

 not formed by the metamorphosis of any part of either the 

 mandibular or the hyoidean arches, such as they exist in 

 the fourth stage of larval development. 



It may be said further, that the columella undoubtedly 

 seems to be developed from the side walls of the auditory 

 capsule in the same way as the stapes, and some appear- 

 ances have led me to suspect that it is originally in con- 

 tinuity with the stapes, but I am not quite sure that such 

 is the case. Are we to conclude, therefore, that the colu- 



