1885.] VISCERAL ANATOMY OF BIRDS. 841 



Crocodile and the Struthiones is not, however, confined to these 

 mennbers of the latter order. Other birds present an identical series 

 of structures. I will now proceed to review these in detail. 



The most complete resemblance to the Struthiones is to be found, 

 so far as my dissections enable me to say, in the Cranes ; and from a 

 classificatory point of view these resemblances appear to me to have 

 some significance. 



I have dissected two species of Cranes, Grus communis and G. 

 monnchus, and the following description applies equally well to both. 



The gizzard and the lift lobe of the liver are enclosed in a separate 

 compartment of peritoneum ; the right lobe of the liver is iu another 

 compartment, separate from the left lobe by the vertical septum or 

 umbilical ligament, which runs back for some way, and is in close 

 contact with the right-hand margin of the gizzard. The intestines 

 are covered by a horizontal membrane, which is attached anteriorly 

 to the gizzard, and in fact clasps it round its whole circumference, 

 so that the upper half of the gizzard projects into the abdominal 

 cavity containing the intestinal coils ; the gizzard, at least its upper 

 surface, appears to be surrounded by a layer of peritoneum reflected 

 from the horizontal septum. The disposition of the viscera and the 

 various septa is therefore identical with that of Rhea and Dromeeus, 

 and almost identical with that of the Crocodile. 



In an interesting paper on the anatomy of the Flamingo', Mr. 

 Weldon has referred to the presence of an exactly similar hori- 

 zontal septum, which he terms "■' pseurlepiplom," in this bird and in 

 many Storks; he describes it in the following words : — "On slitting 

 open the abdominal wall of a Stork in the middle ventral line, the 

 only viscera exposed are the two lobes of the liver and the ventral 

 portion of the gizzard. All the rest are hidden by a thick horizontal 

 septum of connective tissue, stretching across the whole bodj^-cavity 

 from the pericardium to the cloaca." It is evident from this quota- 

 tion that the disposition of the viscera in the Stork is closely similar 

 to what has just been described in the Crane, and only differs in 

 that the lobes of the liver are not enclosed in special compartments 

 of their own. They ai'e stated to be visible on opening the body- 

 cavity, while in the Cranes and Struthious birds the lobes of the 

 liver are not so visible, but require a further dissection of the walls 

 of the compartments which contain them. I have dissected another 

 form of Storks, Abdimia sphenorhyncha, in addition to many of 

 those mentioned by Mr. Weldon, and find that the conditions are 

 identical. 



The Spoonbill (Platalea leucorodia) is a Stork, in so far as the 

 above-mentioned characters are concerned ; I believe that the general 

 consensus of opinion is to regard this bird as closely allied to the 

 Storks, and the foregoing considerations confirm this view. 



In Bucorvus abyssinicus (fig. 2, p. 842) the septa are in the main 

 similar to, but present certain variations from, the types which have 

 been already described. On opening the body-wall the gizzard was 



' P. Z. S. 1883, p. 639. 



