Fig. 1 Cut plane of positive wax-plate model. Original model 80 X enlarged. 
Figure reduced to 50 X. Cut parallel to the pleura, 3 cm. apart from it. Pleural side. 
The larger cavities shown in the figure are air-sacs. The smaller recesses in their 
walls are alveoli. 
Fig. 2° Cut plane of the positive wax-plate model. Magnification same as figure 1. 
3 em. apart from the former cut plane. Pleural side. The larger cavities are. 
alveolar ducts and air-sacs. 
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