WM BA YLlSS AND E. H. STARLING. inspection of the exposed intestines, although graphic methods have been employedby Openchowski, Mislawski, Bunch, Courtade and Guyon and other French authors. Although many of the observations recorded in the following pages might have been obtained from a nmere inspection of the exposed intestines, a fuller analysis of the factors involved in their causation would have been impossible without recourse to the graphic method; and there is no doubt that some of the discrepancies on record have been due to the neglect of such methods.

Contraction of the circular coat of the intestine will diminish the lumen, and in certain conditions of the gut may increase it in length. Contraction of the longitudinal coat will shorten the gut and might theoretically cause a slight increase in its transverse diameter. This increase is however nealigible. The most convenient way of recording the contractions of the circular coat is to introduce into the lumen a capsule of fine rubber, which is tied on to the end of a small metallic tube about 5 inches in length. This may be inselted either through the cut end of a loop of intestine, which is then ligatured tightly round the tube, or better through a smalllongitudinal incision in the unattached margin of the intestine. After the insertion of the tube the incision is closed by two stitches of fine thread, one of which is taken round the tube. The capsule is distended with air under a pressure of about 10 cm. of water, the capsule being connected through a small water manometer to a piston recorder which records the movements of the water-column and so the contractions of the circular coat at the level of the capsule. In manv cases it is useful to be able to register the contractions of the muscular wall without the introduction of any foreign material into the gut. For this purpose we made use of an instrument which we may call an enterograph, by means ofwhich one may record the contractions of either the longitudinal or circular coat, or of both coats simultaneously. The construction of the enterograph will be evident from the diagram.