406 DR. J, MURIE ON THE EMU. [Apr. 11, 



land," accompanying these by figures, comparing the trachea of the 

 Galeated Cassowary, the Emu, and Golden-eyed Duck. 



A notice of Knox's papers followed in ' Froriep's Notizen,' no. 127, 

 March 1824. 



In the last-mentioned Journal, no. 1/7, in November of the same 

 year, a short account was given of a dissection performed by Dr. 

 Wedemeyer* in 1822, wherein the claim of the priority of having 

 discovered the tracheal sac in the Emu was asserted, evidently un- 

 aware of Fremery's earlier observation. 



A full translation of Dr. Knox's two papers appeared afterwards 

 in Meckel's 'Archiv fiir Anatomie und Physiologic,' 1832, p. 263, 

 &c., with footnotes apparently by Meckel himself; for there suc- 

 ceeds the concluding part of a long Essayf upon the Anatomy of 

 the Indian Cassowary by him, and in which he alludes to the au- 

 thors I have above referred to. In his ' Systematic Treatise on 

 Comparative Anatomy,' Meckel j again recalls the opinions of the 

 previously cited observers. 



At the Meeting of the British Association in Bristol in 1836 (Re- 

 port, p. 97), Dr. Macartney laid before the Section of Zoology and 

 Botany " An Account of the Organ of Voice in the New Holland 

 Ostrich ;" and as nothing is said respecting what had already been 

 published, I presume from his statement that he considered the fact 

 new to science. Professor Owen, in his * Memoir on the Anatomy 

 of the Southern Apteryx (Trans. Zool. Soc. vol. ii. p. 279, com- 

 municated in 1838) §, takes notice of Fremery's discovery; but he 

 did not find such a structure existing in the Apteryx. Wagner 

 mentions it in his ' Lehrbuch der Zootomie.' And, finally, Carus 

 figures it in his and D' Alton's ' TabulcC Anat. compar. illust.' 1848, 

 pars vii. tab. 6. fig. 2. 



I have been induced thus historically to call attention to accounts 

 of the tracheal pouch of the Emu, because 1 find that later writers 

 upon the Struthious Birds have not given sufficient importance to 

 these observations upon this singular organization. Such a structure 

 along with other anatomical diff'erences, well pointed out both by 

 Meckel and Knox in the papers cited, should fairl)"^ be taken into 

 account and balanced with other characters, whether dermal or 

 osteological, in order to arrive at not only a natural classification of 

 the family, but its relation to allied groups. 



Although the aforesaid sac has so often been made the subject of 

 remark, no one seems to have figured the most important feature in 

 connexion with it — namely, the open anterior slit in the tracheal 

 rings. Dr. Knox's illustration is defective, inasmuch as it is small, 



* " Der mit der Luftrohre des Emu Casoars in Verbiudung stehende musku- 

 lose Beutel," Froriep's Notizen, 1824-25, p. 7. 



t Tlie first part of which appeared in the ' Archiv.' for 1830, p. 200. 



X Tiaite General D'Anatoruie Comparee par J. F. Meckel, traduit de I'alle- 

 mand ])ar Dr. Th. Schuster. Paris, 1838, x. p. 402, 



§ Tlie disposition of tlie sac to tlie tracliea is therein correctly stated ; but in 

 Prof. Owen's more recent ' Anatomy of Vertebrates,' J866, ii. p. 220, a sHp evi- 

 dently has occurred, in the statement that the cartilaginous rings are wanting 

 pusteriorlij (whereas anteriorly undoubtedly must have l)een meant). 



