Figure 17_e_ is a short distance posterior to the figure just described. The liver is cut through its middle region and forms a large, darkly staining, reticular mass on the left side of the figure. The digestive tract is seen at two places to the right of the liver; the smaller and more ventral of these openings (_i_) may be called the intestine, while the larger is evidently the stomach (_i′_). The body wall is here unfused and becomes suddenly thinner as it passes upward into the amnion (_a_). The Wolffian tubules (_wt_) form a very conspicuous mass on either side of the mesentery, in close connection with the posterior cardinal veins (_pc_). In the mesoblast between the dorsal aorta (_ao_) and the notochord are two small, irregular, darkly stained masses (_sy_). These are shown in the preceding two figures, but were not mentioned in the description. They may be traced through a great part of the length of the embryo back of the head region; at intervals corresponding in length to the distance between the spinal ganglia they are enlarged, while between these enlargements they are very small in cross-section. At certain points a small blood-vessel is given off by the dorsal aorta to the immediate neighborhood of each of these small areas. Although they show no connection with the central nervous system, these structures appear to be the rudiments of the sympathetic nerves. Figure 17_f_ is in the region just in front of the hind legs. The abdominal walls are here unfused, and into the unenclosed body cavity projects the intestine (_i_), supported by a narrow mesentery and surrounded by a comparatively thick mass of mesoblast. The Wolffian body and duct form a mass of considerable size on each side of the mesentery. The Wolffian body is cut near its posterior end and consists of smaller tubules than in the more anterior regions. The Wolffian ducts (_wd_), on the other hand, are very large and are much more clearly distinguishable from the Wolffian tubules than in the preceding sections. The Wolffian ridges (_wr_) are very marked projections on the sides of the body, and in a region farther caudad become especially developed as the posterior appendages, to be described in connection with the following section. Both spinal ganglia are shown in this figure (_sg_), and in connection with the left ganglion the spinal nerve (_sn_), extending ventrally as far as the level of the Wolffian duct. The sympathetic nerve rudiments do not extend so far caudad as the plane of this section. The dorsal end of each muscle plate (_mp_) is seen, in this and other sections, to be slightly enlarged to form a round knob; this knob contains a distinct cavity (not shown in the figure), the myocœl.