732 
REMARKS ON COMPOSITION OF THE BLOOD. 
much as the l-2500th. Their form also is different, the white 
being globular-shaped bodies, and not flattened discs. Again, 
their contents are found to be granular when viewed with a 
microscope, which gives them a dark dotted-like appearance 
totally unlike the red cells. 
Physiological anatomists are not agreed as to the origin and 
use of the white cells ; but by most they are regarded as 
identical with the cells w r hich are met with in the chyle before 
this fluid is mingled with the blood proper ; and certainly 
they would appear not to be essentially different from chyle- 
cells when microscopically examined. Some have considered 
them as ministering directly to nutrition, by the setting at 
liberty of their contents, which are then found to have a 
tendency to fibrillation; while others have thought that they 
were the elaborators of the albumen into fibrine. Others, 
again, consider that they originate the red cells by a higher 
degree of development, and this probably is their chief use. 
The circulation of the white cells through the vessels is 
slower than that of the red; and as they are often found 
close to the sides of the interior of the capillaries, as if ad¬ 
hering thereto, and out of the principal force of the passing 
current, this circumstance has given support to the view of 
their ministering immediately to nutrition. The opinion 
receives some further confirmation from the fact that wherever 
active development is going on, there is always found a 
relatively greater number of these cells. 
The blood of plethoric animals is rich in white cells: 
besides which these bodies seem to have a remarkable tendency 
both to increase in number and to accumulate in the vessels 
w r hen diseases of an inflammatory nature supervene on such 
a state of system. In that abnormal state of the blood, also, 
which is ordinarily termed buffy-blood, and which belongs 
especially to many inflammatory affections, the white cells 
help in a great degree to make up the so-called sizy or buffv 
crust of the blood. We thus see that variation in their 
number and also in their comportment within the vessels takes 
place when disease exists, showing that they, in common 
with every other constituent of the blood, undergo important 
changes under such untoward circumstances. 
We must not, however, anticipate that which has to be 
stated with reference to blood-diseases ; and, therefore, having 
now described the chief constituents of the circulating fluid, 
and shown the several important offices which each fulfils in 
the promotion of health and development, we purpose to con¬ 
clude the present paper, intending in our next to speak of the 
circulation of the blood and the phenomena connected there- 
