nk" meant therefore "drunk as a blood," "drunk as a lord." The
expression came into common colloquial use as a mere intensive, and was
so used till the middle of the 18th century. There can be little doubt
that the use of the word has been considerably affected by the idea of
blood as the vital principle, and therefore something strong, vigorous,
and parallel as an intensive epithet with such expressions as
"thundering," "awfully" and the like.

ANATOMY AND PHYSIOLOGY

In all living organisms, except the most minute, only a minimum number
of cells can come into immediate contact with the general world, whence
is to be drawn the food supply for the whole organism. Hence those
cells--and they are by far the most numerous--which do not lie on the
food-absorbing surface, must gain their nutriment by some indirect
means. Further, each living cell produces waste products whose
accumulation would speedily prove injurious to the cell, hence they must
be constantly removed from its immediate neighbourhood and indeed from
the organism as a whole. In this instance again, only a few cells can
lie on a surface whence such materials can be directly discharged to the
exterior. Hence the main number of the cells of the organism must depend
upon some mechanism by which the waste products can be carried away from
them to that group of cells whose duty it is to modify them, or
discharge them from the body. These two ends are attained by the aid of
a circulating fluid, a fluid which is constantly flowing past every cell
of the body. From it the cells extract the food materials they require
for their sustenance, and into it they discharge the waste materials
resulting from their activity. This circulating medium is the blood.

Whilst undoubtedly the two functions of this circulating fluid above
given are the more prominent, there are yet others of great importance.
For instance, it is known that many tissues as a result of their activity
produce certain chemical substances which are of essential importance to
the life of other tissue cells. These substances--_internal secretions_
as they are termed--are carried to the second tissue by the blood stream.
Again, many instances are known in which two distant tissues communicate
with one another by means of chemical messengers, bodies termed
_hormones_ ([Greek: ormaein], to stir up), which are produced by one
group of cells, and sent to the other group to excite them to activity.
Here, also,