Abiogenesis means spontaneous generation of organism from non-living matter. Aristotle and Von Helmont was supporter of this theory. This theory was disapproved by Redi.
In birds bones are hollow. These bones are known as pneumatic
i.e., bone marrow absent in bones of birds.
Bones of fish, reptiles, amphibians and. mammals have bone marrow. Synthesis of blood corpuscles takes place in bone marrow.