108 GEO. S. HUNTINGTON 
Right lung: D' arises from the caudal border of the eparterial 
bronchus. It carries three main buds, directed mesad, dorsad 
and laterad, each studded with several smaller evaginations. 
Vig. 1 Uterine embryo of Didelphis marsupialis, L. 10mm. Princeton Uni- 
versity Embryological Collection. Reconstruction of lung and pulmonary art- 
ery. X 150. Ventral view. LHp., eparterial bronchus; A., ascending branch of 
first left ventral hyparterial bronchus; V!-V4, ventral hyparterial bronchi; Cd., 
right cardiac bronchus. 
D? is the largest member of the dorsal series and presents the 
same tripartid unfolding. 
D*, smaller, shows a reduced trefoil en D* is a single 
aerate: directed bud. 
