674 TRANSACTIONS OF SECTION I. 
but is condensed as small granules or in masses in the cytoplasm, and it is 
wholly absent from the cell nucleus. It occurs also in the polar processes of 
the cell, but, except in certain sympathetic nerve cells, it does not extend into 
the axon. The reaction is not due to chlorides or phosphates, and the substance 
responsible for it is extracted quickly from the cell by water and alcohol. 
It is most abundant in the cells of the sympathetic nervous system, and it occurs 
in great abundance in the cells of the nerve ganglia of the leech. It has been 
found also that the cells of the medulla of the suprarenal glands give the reaction 
in a marked degree, a point that is of interest since the cells of the medulla of 
the suprarenals are regarded as altered nerve cells whose function is the secretion 
of the hormone, adrenalin. 
It is suggested that the substance responsible for the reaction belongs to 
the oxy-phenyl class of compounds, as these readily reduce nitrate of silver in 
the light, and that it is allied to adrenalin, which is also an oxy-phenyl com- 
pound, and which may be prepared from it by the medullary cells of the supra- 
renal gland. Its occurrence in nerve cells is, apparently, an indication that the 
nerve cell is, potentially, if not actually, a secreting structure. 
TUESDAY, SEPTEMBER 16. 
The following Paper was read :— 
The Biochemistry of the Neurone. By Dr. F. W. Mort, F.R.S. 
Joint Meeting with Sections D and K.—See p. 527. 
The following Papers were then read :— 
1. Considerations bearing on the Study of the Blood and Vascular 
System. By Professor GrorcEs Dreyer and Dr. E. W. AINnLEY 
WALKER. 
1. In association with Dr. W. Ray, the-authors have already shown that in a 
series of mammals, both wild and tame, the volume of the blood is proportional 
to the body surface of the individual throughout any given species. It can be 
calculated from the formula B = a where W is the weight of the animal, n is ap- 
proximately 0°72, and & is a constant to be ascertained for each particular species. 
2. Further experiments carried out in association with Dr. H. K. Fry show 
that in birds the same relation holds, and that the blood volume of fowls, 
pigeons, sparrows, and ducks follows the formula B = we 
I~ 
, having the value 
0°70-0°72, and the constant % possessing a value which changes with the species. 
This formula also accurately represents the area of the body surface in these 
birds, as was shown by actual measurement in a large number of cases. 
3. That this relation is peculiar to warm-blooded animals and is associated 
with their homoiothermic character appears to follow from unpublished experi- 
ments carried out on cold-blooded animals (lizards and frogs) by Dr. Fry. His 
observations show that in these animals the blood volume is neither proportional 
to the body surface, nor to the body weight. But it varies as a power (greater 
than unity) of the body weight. Thus in the cold-blooded animals the percent- 
