And this was the sum of the Martian organs.  Strange as it may seem
to a human being, all the complex apparatus of digestion, which makes
up the bulk of our bodies, did not exist in the Martians.  They were
heads--merely heads.  Entrails they had none.  They did not eat, much
less digest.  Instead, they took the fresh, living blood of other
creatures, and _injected_ it into their own veins.  I have myself seen
this being done, as I shall mention in its place.  But, squeamish as I
may seem, I cannot bring myself to describe what I could not endure
even to continue watching.  Let it suffice to say, blood obtained from
a still living animal, in most cases from a human being, was run
directly by means of a little pipette into the recipient canal. . . .