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Show 1889.] FAT-BODIES OF THE SAUROPSIDA. 605 pointing backwards, which in the hinder region extends up the sides as far as the kidneys. < I believe that the views to which I have been led largely agree with those of M r . Beddard1. W e agree that the condition in Monitors to which he has drawn attention is unlike that in other Lizards and well worthy of study. There are, however, certain of his conclusions and suggestions which, after a careful examination of Monitors2 and other reptiles, I a m unable to accept. Beddard says (1, p. 100) : " In Monitors when the body-walls are cut open and reflected, the alimentary viscera are not exposed as they are in Iguana. A loose membrane covers the viscera; the membrane looks as if it were simply the lining peritoneum of the abdominal cavity which had got separated and detached from the abdominal parietes; this is, however, not the case; an examination by the aid of the microscope showed clearly that a layer of peritoneum covers the abdominal musculature, and is quite distinct from the horizontal membrane; in Varanus griseus the peritoneal layer was particularly distinct, for the reason that it contained numerous pigmented corpuscles.... This horizontal membrane also separates the kidneys from the reproductive glands ; the latter lie internally to it; the kidneys are placed outside it." The italics in the above quotation are mine, and serve to indicate the passages to which I would call attention. It is certain that the space surrounding the fat-bodies and separated from the peritoneal cavity containing the intestines, by the "horizontal" membrane that wraps round these, is not due merely to some accidental or post-mortem separation of this m e m brane from the body-wall; and that the space in question, which I will term the circumadiposal cavity (ca.c, in figs. 14-17), is lined by a smooth membrane which covers the body-wall, and is reflected to form the exterior layer of the so-called " horizontal membrane." I presume that, in saying that the microscope shows this lining membrane to be peritoneum, Beddard merely means that it forms a natural free surface, and is not a rough line of parting produced by a tear. More than this the microscope could not well prove ; nor does the presence of pigment do so, since pigment, though common in the peritoneal lining of the body-cavity,is not confined to this layer. It may occur in the more external and muscular layers of the body-wall, as can be seen in transverse sections of Snakes. Now, in no reptile examined have I observed any connection between the peritoneal cavity proper and the circumadiposal cavities; and since (as Beddard, judging by his paper (1, p. 100), would admit) the circumadiposal cavities of the Monitors are homologous with the inconspicuous spaces round the fat-bodies in other Lizards, which there is no good reason to regard as parts of the peritoneal cavity, I hold that until such a connection shall 1 I would acknowledge the kind and practical interest that Mr. Beddard bas taken in m y work. 2 I have examined two specimens of Varanus indicus, two of V. nigro-punctatus, and some ten small specimens of V. niloticus. |
