(Darwin 1897, 123) referred to the term “spinal marrow” when comparing the shape of the foramen magnum in wild rabbits versus large “lop-eared” rabbits.  After looking up the term “marrow,” (which refers to the fat in the middle of bones from which blood is formed,) I found that the term is also used to refer to the spinal cord.  Interesting.

 

Bibliography:

Darwin, Charles.  The variation of animals and plants under domestication, Volume I.  New York:  D. Appleton and Company, 1897.

Resources:

Darrell Barnes Science and Nature YouTube Channel