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Show 1 5 0 MR. F. E. BEDUARD ON THE VISCERAL [J une 7, Until very near its posterior end the trachea forms merely a gutter along its ventral side, that is it opens freely into it throughout. Posteriorly, however, there is a distinct tendency for the lung to be connected only at intervals with the trachea, a hint as it appears to me-of the commencing independence of the two parts of the pulmonary apparatus. The thoracic lung is very plainly a respiratory organ down to about the middle of the liver and to a less extent posteriorly. Its texture is like that of many other serpents, but not like that of Hydrus (see p. 153). It presents, as is shown in the accompanying drawing (text-fig. 26), Text-fig;. 26. k t a p s A portion of the internal surface of the lung of Platiiurus colnhrinits. a honeycombed and perfectly regular structure. The depressions are naturally hexagonal through mutual pressure. 1 coidd find no difference in the structure of tracheal and bronchial lungs. The bronchus is traceable for a long way down the liver. At a. little distance behind the posterior end of the liver (about ^ of an inch), the lung, which has gradually become very narrow, widens out into a, thin-walled dilatation of quite twice its former width. This dilatation is of an inch long and fusiform in shape. It is thin-walled, and thus contrasts with adjacent regions of the lung; but on its inner surface a honeycomb pattern is visible, the depressions, however, being very slightly marked. Behind this dilatation the honeycomb structure was also plainly visible. The greater part of the lung in fact seems to be utilised as a respiratory organ. It is particularly noteworthy that the posterior region of the |