REPORT ON THE SPHENISCID^. 



211 



septum resembles that of Pygosceles, while in Spheniscus minor the complete absence of 

 a septum tracheae is paralleled by the case of one specimen of Eudyptes chrysocome from 

 Tristan d'Acunha. 



A reference to the table on pp. 211-213 shows, moreover, that the dimensions of the 

 tracheal septum do not constitute a generic distinction, that they are not constant in 

 different specimens of one and the same species, and that they are not in any way 

 characteristic of sex. 



Remarks. — So far as I can ascertain, the discovery of the presence of a tracheal septum 

 in the Penguins is due to Jaeger,^ who in a paper in Meckel's Archives described the 

 tracheal septum as it occurs in Aptenodytes demersa. In a footnote he likewise refers to 

 the occurrence in Procellaria of a corresponding subdivision of the windpipe by means of 

 a longitudinal septum, and observes that in that genus the septum is more limited than 

 in Aptenodytes. Jaeger's observations have since been copied into nearly every text-book 

 of comparative anatomy, but I cannot find that they have been extended to other species. 

 At least neither Eeid,^ in his communication on the anatomy of Aj)tenodytes patachonica, 

 nor Garnot,^ in his anatomical account of AjJtenodytes demersa, refers to the peculiarity in 

 question.* 



1 Theilung der Luftrolire durch eine Sclieidewand bei der Fettgans, Aptenodytes demersa, Meckel's Archiv fiir 

 Anat. imd Physiol., 1832, p. 48. 



2 Proc. Zool. Soc. Lend., 1835, p. 132. 



5 Anatomical account of Aptenodytes demersa in "Remarques sur las Zoologie des iles Malouines," par M. P. Gariiot 

 in Annales des Sciences Naturelles, Zoologie, 1826, torn. vii. p. 53. 



^ Since this paragraph was written, Mr. W. Forbes has published his observations on the anatomy of the Petrels, 

 and has pointed out in several of these birds the existence of a tracheal septum similar to that described above in the 

 Penguins. — Challenger "Reports, Zoology, vol. iv., p. 32. 



' In this table the dimensions of the trachea, &c., are given in English inches. 



