Dr. Beale, on Nutrition , 
81 
place in pre-existing germinal matter. The white blood- 
corpuscles, therefore, are themselves composed of living mat- 
ter, which is nourished, and they cannot as white blood- 
corpuscles contribute to the nutrition of any tissues whatever. 
With regard to the red blood-corpuscles, it seems to me pro- 
bable that they play a highly important part in equalising 
the temperature in all parts of the body, taking away heat 
from parts whose temperature is above the normal standard, 
and contributing heat to textures which are colder than they 
should be. At the same time it must be borne in mind that 
the red blood-corpuscles themselves are gradually undergoing 
disintegration ; and although it seems most probable that the 
constituents resulting from their decay are eliminated from 
the body in the form of urinary, biliary, and other excremen- 
titious matters, it is not unlikely that some of the products 
may take part in nutrition. 
Upon the whole, however, it seems probable that the con- 
stituents which form the pabulum of the tissues are those 
which are contained in the serum of the blood ; and it is im- 
possible to conceive how minute quantities of pabulum prone 
to undergo rapid change could be more perfectly and equally 
distributed to the textures, without its composition being 
materially changed, than in the thin layers which each red 
blood-corpuscle carries upon its surface, and smears, as it 
were, upon the walls of the capillary vessel distributed to the 
tissue. The arrangement is such as to reduce to a minimum 
the chances of alteration in the composition of the nutrient 
fluid as it traverses the vessels in different parts of the body. 
From a careful consideration of the facts, I cannot help 
drawing the inference that the serum is the pabulum ; that 
the red-blood corpuscles are concerned in its distribution, 
and in preventing changes in the composition of the great 
mass of the blood, as certain constituents are removed from 
it or poured into it ; and that the white blood-corpuscles are 
masses of germinal matter concerned in the formation of the 
serum, as well as of the red blood-corpuscles. In support of 
this view, I would venture to call attention to the following 
points : 
1st. That fibrous tissue, bone, cartilage, muscular and 
nervous textures — the two last as perfect and, as far as we 
can make out, far more delicate, elaborate, and beautiful than 
any of the tissues of vertebrate animals — are formed, and with 
wonderful rapidity, in many of the lower creatures quite des- 
titute of a nutrient fluid containing bodies corresponding to 
the red blood-corpuscles of the vertebrate blood ; and that in 
all these cases the nutrient fluid is clear, transparent, colour- 
