E884 | Fsychology. 211 
cury, were found to have no direct effect whatever upon the 
quantity of blood sent out from the left ventricle at each systole. 
Since the pulse rate is not altered, the work done by the left ven- 
tricle varies directly as the arterial pressure against which it 
works, within the limits named. For how’much wider limits than 
those given this may hold true was not determined. There is 
every reason to believe that under normal conditions the force of 
the systole is more than stifficient to completely empty the ven- 
tricular cavity, and since, with arterial pressures from 58 to 147 
millims., the quantity of blood ejected at each systole remains 
constant, it seems probable that within these limits, at least, the 
force of the ventricular contraction is not influenced by variations 
in arterial pressure, but remains maximal throughout. 
Variations of venous pressure on the right side of the heart in- 
fluence in a marked manner the outflow from the left ventricle. 
As the general result of the experiments it was found that the 
outflow from the left ventricle, and consequently the work done 
y it, increases with the venous pressure, but not proportionally, 
up to the point of maximum work, 
Variations in the rate of beat of the heart were obtained by 
koas or cooling theblood supplied to it. The general result may 
outflow from the ventricle at each systole are not, however, in- 
versely proportional to the changes in the pulse-rate. The total 
| November, 1883 
4 PSYCHOLOGY. 
INTELLIGENCE IN A PoINrER.—Don was a pointer dog, of large 
> nce, that I shot with over forty years ago. At that time the 
Were grouse were abundant in our wild prairies. The birds 
nar frequently found in particular localities in different 
the of the day. They affected the low grounds or swales, where 
and os, Was long, in the heat of the day, and in the morning — 
cloudy dae they resorted to the high, rolling prairie. In a cool, 
Dee sabe they were likely to remain on the high grounds. 
the feld „learned this as well as his master, and when taken into 
deli it was interesting to observe the dog, when on the prairie, 
over th y surveying the ground and then start out and range 
This. same ground his master would have selected. 
’ Peculiar « the result of education and observation, and was not 
= arto Don. I have known many old bird dogs do the same, 
