1887.] IN THE LARYNX OF THE ANUROUS AMPHIBIA. 501 



If the apparatus be held to be of none but physiological significance, 

 the clue to its meaning has yet to be found ; it is clearly in no way 

 associated with the development of the vocal sac, nor is it confined to 

 the males, as might be supposed. In the higher forms, however, it 

 is vestigial and of little or no functional importance ; and there is 

 nothing forthcoming in any one specimen which is not represented in 

 the male of Chiroleptes. These facts, in view of the uniformity of 

 development of the parts in the latter, would seem to rne to suggest 

 that the apparatus has an important morphological significance, and 

 that in the admittedly lowly Australian type the primitive condition 

 is most nearly exemplified. The problem is an interesting one, and 

 further investigation is necessary for its solution. 



Turning, finally, to the question of general morphological import- 

 ance, it is clear that the discovery of the epiglottis in the Amphibia, 

 in the furm and under the conditions here recorded, carries back a 

 stage further the initiation of one more structure peculiarly charac- 

 teristic of Mammals. The interest of this is increased when we 

 reflect upon the identity of the Amphibian epiglottis, which is 

 clearly bilaterally symmetiical, if not actually paired, with the initial 

 pliase in development of that organ in the human subject as observed 

 by His. The facts show that the origin of this typically Mamma- 

 lian structure must be sought in animals lower than the living 

 Lizards \ It would be wide of the mark to form data for discussing 

 the question of Mammalian aflfinities upon it. In view, however, 

 of the anticipation of the ceecum coli in the Common Frog^ and of 

 the excursions made by those Amphibia with suppressed larval meta- 

 morphoses^, in which it is highly probable there may have been 

 foreshadowed the foetal membranes of the Amniota (c/. Huxley, 

 P. Z. S. 1880, p. 660), the facts here recorded can best be regarded 

 as in( icative of similar excursions towards the elaboration of the 

 voice-organ, anticipatory, as has been shown, of the characteristically 

 Mammalian condition. 



' It is of interest bere to note tlie existence of an epiglottis-like flbro-carti- 

 laginous plate in Profapfenis. Attention was first drawn to it by Henle {I. c. 

 pp. 5, 6), and it was shortly afterwards described in full and figured by Biscboflf 

 (" Descr. Anat. du Lcpidosiren paradojca,^' Ann. Sci. Nat. t. xiv. Zool. 1840 

 p. 136). Wiedersheim has refigured it (' Lehrbuch ') and recorded {ibid.) the 

 discovery of an analogous structure in Lcpidosteus. 



^ Huxley, in Huxley and Martin's Elem. Biology, 1875, p. 166. 



■'' Especially iSo/ofrema, Weinland, Arcbiv f. Anat. und Phys. 1854; Hylodsa, 

 Peters andGundlach, Monatsb. Berlin. Acad. 1876; Eanaopisthodon, Boulenger, 

 T. Z. S. vol. xii. 1886 ; Phyllomedusa, v. Ihering and Boulenger, Ann. & Mag. 

 Nat. Hist. vol. xvii. 1886. 



For a resume of the subject generally, with full references and list of species, 

 eee Boulenger on Fhyllwnediisa, op. cit. p. 464. Cf. also Smith and Cope on 

 Jkndrobates, Amer. Naturalist, 1887, pp. 307-311. 



