!^38 THE HAETEIAN ORATIOIf. 



might have been a fitting exhibition for me to go through upon 

 the present occasion, following herein the example of Harvey, 

 ' viliora animalia in scenam adducentis.' I have, however, learned 

 that this very demonstration on the appendix vermiformis of the 

 rabbit has been often performed in Germany, and, indeed, also in 

 England ; and I judged, consequently, that it might be superfluous, 

 as it would not be novel, to exhibit it here and now. 



Having been thus disappointed in my intention of demonstrating 

 something new in this direction, I cast about in another for some- 

 thing of the same character. And in the heart of a bird, the 

 Australian Cassowary (Casuarius australis), killed at Rockingham 

 Bay, lat. i8 deg., on the east coast of that continent, and sent me 

 by my former pupil, J. E. Davidson, Esq., I came upon a structure 

 which I am well assured has never been either described or figured 

 before. It possesses upon this ground some claim upon our atten- 

 tion ; but it possesses stronger claims than any which mere rarity 

 could give it, being a structure which, though it has never been seen 

 in any other member of the class Aves, is largely developed, and, 

 indeed, exactly reproduced in the hearts of certain mammals, and 

 does not fail to be represented, at least rudimentarilj^, in our own. 

 The structure in question is a ' moderator ' band, holding precisely 

 the same relations to the other parts of the right venti-icle in this 

 bird which the band so named by Mr. T. W. King in the 'Guy's 

 Hospital Reports,' vol. ii. p. 122, 1837, holds in many, if not in all. 

 Ungulate mammals. This, I presume, is made plain by a com- 

 parison of the two diagrams (Figures 2 and 3), showing, one of them 

 the heart of this bird, the other the heart of a sheep, with the right 

 ventricle similarly laid open in each case. The advantage, which in 

 the struggle for existence, and specially in that very common 

 phase of it which takes the form of a race for food or from an 

 eater, which an animal with such a muscular band passing directly 

 across the cavity of its right ventricle from its fixed to its movable 

 wall must possess, is not a difficult thing for any man to under- 

 stand who has ever either watched in another or experienced in 

 himself the distress caused by the over-distension of any muscular 

 sac ^ A band of similar function — I do not say definitely of 



. * Since writing as above I have been reminded of what I ought not to have for- 

 gotten, viz. that my friend Dr. Milner Fothergill has discussed this very subject in 

 his work, ^ The Heart and its Diseases, with their Treatment,/ London, 1872, p. 6. 



