844 ON THE VISCERAL ANATOMY OF BIRDS. [NoV. 17, 



adherent to the walls of the <iizzf»rd ; the horizoiit septum is oonti- 

 nuous at the sides with the oblique septum ; it bears a second blood- 

 vessel, which enters the left lobe of the liver, and is fully as large 

 as the vessel on the right side of the body. It appears to me to be 

 permissible to compare these two abdominal veins witVi the two that 

 are found in the Crocodile figured in the drawing (fig. 1, p. 840). 

 In no other birds that I have dissected have I been able to find more 

 than a single "umbilical" or anterior abdominal vein which passes 

 along the falciform ligament to the liver. The lobes of the liver are 

 contained in two separate cavities floored by the horizontal septum, but 

 which are not cut off from the abdomen posteriorly by a membranous 

 band, as they are for example in Bucorvus. Each lobe of the liver is 

 firmly attached to the vertical septum, and by a special membranous 

 band to the oblique septum. The gizzard does not appear to be 

 enclosed in a special sac as in other birds; the horizontal septum covers 

 it above (ventrally), butdorsally there appeared to be no trace of anj' 

 covering of fibrous tissue, the gizzard projecting freely into the cavity 

 which contains the intestines. In other birds this horizontal septum 

 is not developed or not developed to so conspicuous an extent as in 

 the types already referred to. It is absent, for instance, in the 

 StrigidaH, judging, at least, from examples of three species belonging 

 to this family which I have had the o|)porttuiity of dissecting. 



In Pulsatrix torquata, Si/rnium. ulitco and Strix Jiammea there is 

 no trace of the horizontal se|)tnm, except that in all, the gizzard is 

 enclosed in a special sac of |»eritoneum, and is firmly attached to the 

 parietes, as mentioned by Owen in his ' Comparative Anatomy' '. 



In Carpophaga cBnea there is no horizontal septum, nor in 

 Phasianiis eUioti (young). Rhynchotus rufescens agrees with the last- 

 mentioned types in having no horizontal septum ; the gizzard, 

 however, is firmly attached to the left oblique septum, and is enclosed 

 in a delicate but unmistakable peritoneal sac, as in Phasiamis. It is 

 interesting to note that in these structural features the Tinamou is 

 totally unlike the Struthious birds. 



In a subsequent paper I hope to be able to extend these observa- 

 tions to a larger series of birds. I do not wish to deduce any 

 classificatory results from the facts contained in the present paper, 

 which may perhaps be done later ; the main result has been to show 

 that the Ostrich tribe are not more "Crocodilian" in the characters 

 of their abdominal viscera than many other birds. They agree, in 

 fact, very closely with the Cranes and Storks and other birds. In 

 addition to the points of resemblance between Crocodiles and birds 

 indicated by Prof. Huxley, the large " omentum " which covers the 

 intestinal coils in the Reptile evidently corresponds with the omen- 

 tum (pseudepiploon, Weldon) of the Struthiones, Grallatores, &c. 



I Vol. ii. p. 163. 



