Table 3.

Stages of lung development in larger animals compared with that of humans

Stage	Gestational age (days)
	Rabbit	Sheep	Pig	Baboon	Human
Term	32	147	115	168–185	280
Embryonic	Up to 18	Up to 40	Up to 25	Up to 42	Up to 42
Pseudoglandular	21–24	40–80	22–56	Up to 80	52–112
Canalicular	24–27	80–110	56–98	80–120	112–168
Saccular	From 27	110–130	From 99	120–140	From 168
Alveolar	From 30	From 130	From 104	From 140	From 252