Bichat, Marie Francois Xavier 1771-1802.
French physician and founder of histology,
the study of tissues. He studied the organs
of the body, their structure, and the ways in
which they are affected by disease. This led
to his discovery and naming of `tissue', a
basic biological and medical concept; he
identified 21 types. He argued that disease
does not affect the whole organ but only
certain of its constituent tissues.