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Show 416 DR. J. G. GARSON O N T H E [June 19, The right lung is composed of three lobes-an anterior and a posterior dorsal lobe and an anterior ventral lobe. The anterior dorsal lobe is subdivided into an anterior division and a posterior division. The anterior portion hooks forwards and downwards in front of the heart, more or less completely covering the right auricle. The ventral lobe lies against the posterior wall of the left ventricle, and is deeply grooved for the ascending cava. The left lung consists of two lobes-an anterior and a posterior dorsal lobe, the former of which is subdivided into an anterior and a posterior portion. The anterior portion runs directly forwards, while the posterior portion is directed downwards dorso-ventrally. The extreme length of the lungs is about 12 cm., and the extreme depth along the diaphragmatic surface is 9 cm. A portion of the left lung in the form of a small lobule intervenes between the diaphragm and the heart. The heart measures from its base to apex 5*2 cm.; the antero-posterior length from the margin of one ventricle to that of the other is 5 cm.; the transverse diameter is 3*5 cm. The spleen is long and narrow, very similar in all respects to that of the Pig, but differs from that of Dicotyles in being more elongated and not so broad at the posterior end. The mesenteric glands are numerous aud of large size. In some instances several glands are aggregated together so as to form large glandular patches between the folds of the mesentery. The vessels of the mesentery are quite straight, as in the Pig. The brain is of small size, measuring, from the olfactory lobes to the posterior part of the cerebellum, 6*2 cm. in length, and 3*8 cm. in breadth. The fissures and convolutions are well marked, and can Fig. 1. Lateral view, right side; natural size, after being hardened in spirit. readily be compared with those of the common Pig. Adopting the nomenclature proposed by Krueg for the different cerebral fissures1, we recognize the rhinal fissure (Rh) extending along the lower part of the cerebrum on each side throughout its whole length. About the centre of this fissure (figs. 1 and 2), but somewhat nearer the posterior than the anterior end, are the various portions of the Sylvian fissure, the 1 Zeitschrift f. wissensch. Zool. Leipzig, 1878, xxxi. pp. 297-344. |