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Show 1887.] IN THE LARYNX OF THE ANUROUS AMPHIBIA. 499 thinner and more vibratile than the rest, a beautiful parallel striation ; the epiglottis is also membranous, but supported upon a connective-tissue framework, which is densest along the lines of development of its paired outgrowths. Neither epiglottis nor epilaryngeal folds appear to have given attachment to definite muscles ; the epiglottis was very flexible in life ; and although unable to trace a direct muscular connection, I incline to the belief that it was under muscular control. What may be the precise function performed by these interesting structures, I do not pretend to say, but I hold it indubitable that they are concerned in phonation. If this be admitted, a most interesting parallelism becomes obvious between the higher Amniota (Mammalia) and the higher lchthyopsida (Anura) with respect to the appearance of the epiglottis as an accompaniment of specialized laryngeal activity ; and we have good reason for believing that organ to have been primarily connected with phonation-a deduction which all recent investigation into the function of the Mammalian epiglottis upholds. While the epiglottis makes its appearance in the Amphibia as an accessory voice-organ, its development does not appear to be of necessity related to a high development of the vocal sac. Heron Royer has lately described' the larynx of Hgla meridionalis (bary-tonus, Royer) ; in it, in spite of the immense development of the gular sac, there does not appear to be anything present of the nature described above. Royer has further pointed to specific differences between the larynges of H. arborea and H. meridionalis; Mr. Boulenger, however, informs me that he has found the same to be of no specific value, and I fully share that belief. Thanks to Frof. Huxley and Mr. Boulenger, I have been able to examine a series of specimens, with the result set forth in the following table2:- a. Epiglottis present: epilaryngeal folds confluent behind. Calyptocephalus gayi. 3 • Ceratophrgs americana. 3 • Chiroleptes australis. Adult 3 • Heleioporus albopunctatus. 3 Leptodactylus pentadactylus. 3 • b. Epiglottis present; epilaryngeal folds not confluent behind. Hyla carulea. 3 • * dolichopsis. 3,2' (A second 3 showed no traces.) Hyla lichenata. 2 • *Rana pipiens. 3. 2 c. Epiglottis present, but small; epilaryngeal folds absent. *Bombinator bombinus. 3 • Chiroleptes alboguttatus. 3 australis. 3 juv. * Rana esculenta. 3, 2 * temporaria. 3, 2 1 " Note sur une forme de Rainette nouvelle pour la faune franchise," Bullet. Soc. Zool. d. France, vol. ix. 1884. 2 One specimen only examined, excepting those marked *. |
