John Lewis Bremer 



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nionary arteries, often two, as is suggested in Fig. 5, x, y, while in a 

 pig of 11.0 mm. the two arteries, along a considerable part of their 

 length, have merged into one channel. Fig. 6. Meanwhile the upper or 

 proximal part of the right pulmonary artery, which often shows signs of 



Fig. 9. Pig of 20.0 mm. 

 diameters. 



Frontal series No. 61, sections 270-279. X 80 



irregularity, such as a double origin. Figs. 4 and 7, D, ceases to increase 

 in size, then grows smaller, and soon becomes obliterated, so that all 

 the blood to both lungs flows through the left pulmonary ai-tery. This 

 gradual change is shown at D, Figs. 5, 6 and 7, and in Fig. 8, where 

 only the remains of the right artery are seen. For a little while after 

 the obliteration of the lumen, a cord of connective tissue marks the 



