476 WILLIAM SNOW MILLER 
conclusively that stomata are, as I have maintained in the case 
of the pleura, artifacts. The statement of Flint, who has studied 
alveolar pores from the embryological side that they are not nor- 
mal structures, should go a long way in settling this question of 
alveolar pores. 
SUMMARY 
1. The mode of division for the main series of bronchi is mo- 
nopodial. 
2. There are present in the cat’s lung two series of bronchi to 
which the name ‘bronchiolus respiratorius’ is applicable. 
3. The sacculi alveolares do not communicate directly with the 
ductuli alveolares; but, between the two, atria are interposed. 
4. The lobule is the natural unit of structure. It consists of 
a ductulus alveolaris with its atria, sacculi alveolares, blood ves- 
sels, lymph vessels and nerves. 
5. Communications between adjoining sacculi alveolares, the 
so called alveolar pores, do not exist in the normal lung. 
6. The mode of division for the smaller bronchi is a mixed dich- 
otomy and monopody. 
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AN, 
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1897 Développement des bronches principales chez le mouton. Compt. 
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