CARNIVORA. 



481 



true tympanum, taking the place of the mastoid 

 process, and probably performing the same 

 office as the mastoid cells. This, in many, 

 forms a large rounded process beneath the 

 cranium. In the cats it is remarkably large 

 and globose ; in the bear, on the contrary, it is 

 not visible externally. The object of this en- 

 larged cavity is doubtless to give additional 

 volume to the sounds which are brought to it, 

 a circumstance especially required by the noc- 

 turnal habits of those species in which it is 

 most largely developed. The fenestra rotunda, 

 which is covered by a membrane stretched 

 across it, is believed by Cuvier to be intended 

 for the reception of the sounds produced by 

 the resonance of the bony case just described ; 

 an opinion which is perfectly consonant with 

 that of Scarpa, who considers the hole in 

 question, with its membrane, as a sort of se- 

 condary tympanum. The fenestra rotunda is 

 the larger of the two apertures of communi- 

 cation with the internal ear in the present order 

 generally ; in some of the most nocturnal, the 

 cats and the civets, it is almost double the size 

 of the fenestra ovalis. The passage answering 

 to the Euslachian tube is remarkably short and 

 can scarcely be called tubular; in the cats and 

 civets it is nothing more than a narrow cleft in 

 the suture which unites the tympanum to the 

 true petrous bone. 



The organ of smell is generally extensive in 

 the carnivorous animals, and in addition to the 

 principal apparatus of this sense, the different 

 sinuses which augment the nasal cavity, par- 

 ticularly the frontal, are of considerable extent, 

 especially in the canida. But the most re- 

 markably developed of the surfaces on which 

 the pituitary membrane is distributed, are 

 those of the superior and inferior turbinated 

 bones. The inferior are very complicated in 

 their convolutions in the dogs, the bears, seve- 

 ral of the cats, and particularly in the otters 

 and the seals. This complication consists of 

 repeated and multifarious bifurcation ; and the 

 ultimate divisions of this bone, which all as- 

 sume a parallel direction, form a great number 

 of channels which the air traverses in the act 

 of inspiration, and which are all covered by 

 the pituitary membrane. The ethmoidal cells 

 and the superior turbinated bones are likewise 

 greatly developed in the Carnivora, and par- 

 ticularly in those in which the before-men- 

 tioned structure of the inferior turbinated 

 bones is most conspicuous a remark which 

 also applies to the numerous foramina in the 

 cribriform plate of the ethmoid. 



In the bear, and particularly in the coati, 

 the cartilages of the nose form a complete tube, 

 which is articulated moveably to the bony nos- 

 trils. The same structure is still more remark- 

 able in the mole. 



The organ of taste. The structure of the 

 surface of the tongue in the Felida is very 

 remarkable with regard to the characters of the 

 various papillae with which it is furnished. The 

 edges are everywhere covered with small soft 

 conical papilla, as well as with the papilla 

 petioluta:, such as are found in most other 



VOL. I. 



animals. The whole of the middle part is 

 covered with papilla of two kinds very dif- 

 ferent from each other, and these two kinds are 

 arranged in alternate rows in a quincuntial 

 order. Those of one kind are soft, rounded, 

 and appear to consist of bundles of filaments, 

 which are supposed by Cuvier to be the ulti- 

 timate extremities of the gustatory nerves, 

 though this opinion appears from the recent 

 observations of Breschet to be very doubtful* 

 The others are conical and pointed, and each 

 of them is covered by a sharp horny case 

 curved a little backwards. It is these horny 

 spines which render the tongue of the cats and 

 the civets so exceedingly rough as that their 

 continued licking would soon abrade the hu- 

 man skin. The tongue in all the other Carni- 

 vora scarcely differs in its structure from that 

 of the human subject. 



Secretions. The urine. The structure of 

 the kidney in some of the Carnivora is wor- 

 thy of notice. Instead of being a compact 

 and united mass as in man, it is subdivided 

 into numerous portions similar to those of the 

 human foetus. In the cats this division is 

 scarcely perceptible, the surface being only in- 

 terrupted by superficial fissures or sulci. But 

 in the bears, the otters, and the seals, the sepa- 

 ration is so deep as to resemble in some sort 

 a bunch of grapes. In the otter there are only 

 ten of these divisions in each kidney ; in the 

 bear there are about fifty, and in the seal from 

 a hundred and twenty to a hundred and forty. 

 As this peculiarity of structure is found to 

 exist in a still more remarkable degree in the 

 cetacea, Cuvier has suggested whether it may 

 be connected with the occasional longer or 

 shorter suspension of respiration, as it obtains 

 in the cetacea, the seals, the otters, which 

 are often submerged, in the bears which re- 

 main torpid during the winter, and in the 

 human foetus which has never breathed. Its 

 existence, however, in the elephant, the ox, 

 and many other animals whose respiration is 

 never interrupted, renders this explanation, 

 as Cuvier himself observes, extremely unsatis- 

 factory. 



The existence of follicles producing a pecu- 

 liar secretion is not an uncommon circumstance 

 in several orders of the mammifera, as well as 

 in many reptiles. In the Carnivora these fol- 

 licles are found in almost all the genera, and 

 in some attain to a large size. They are situ- 

 ated one on each side of the anus, and the 

 excretory duct opens near the termination of 

 the rectum. The substance usually secreted 

 by these glandular surfaces is strongly odor- 

 ous, and in some cases intolerably fetid. The 

 annexed engraving (fig- 202) is taken from 

 a specimen of Gallictis vittata, which I dis- 

 sected some time since, and is selected, 

 because it has not been before figured, and 

 because the glands are of large size and very 

 distinct. Each follicle is covered by a muscle 

 of no inconsiderable strength, the object of 

 which is to compress the follicle, and to 

 force out the secretion through the duct. One 

 of the follicles is represented covered by its 



2 i 



