Hardened _in situ_. _1_, Left bronchus; _2_, pulmonary veins; _3_,
pulmonary artery.
]
They are divided into lobes by deep =fissures= (Incisuræ interlobares).
The =left lung= is divided into =three lobes=, named from before
backward =apical=, =cardiac=, and =diaphragmatic=. The =right lung= has
=four= or =five lobes=; the =apical lobe= is much larger than that of
the left lung, and occupies the space in front of the pericardium,
pushing the mediastinum against the left wall;[133] the =mediastinal
lobe= resembles that of the horse, while the =cardiac lobe= is often
divided by a fissure into two parts. The apical lobe of the right lung
receives a special bronchus from the trachea opposite the third rib. The
right lung is adherent to the trachea from the second rib backward.
[Illustration: