ematograph and the ultra-microscope we can see what no other forms of photography can reproduce.
"I have secured these pictures so that I can better mass up the evidence against a certain person in this room. For in the blood of one of you is now going on the fight which you have here seen portrayed by the picture machine. Notice how the blood corpuscles in this infected blood have lost their smooth, glossy appearance, become granular and incapable of nourishing the tissues. The trypanosomes are fighting with the normal blood cells. Here we have the lowest group of animal life, the protozoa, at work killing the highest, man."
Kennedy needed nothing more than the breathless stillness to convince him of the effectiveness of his method of presenting his case.
"Now," he resumed, "let us leave this blood-sucking, vampirish tse-tse fly for the moment. I have another revelation to make."
He laid down on the table under the lights, which now flashed up again, the little hollow silver cylinder.
"This little instrument," Kennedy explained, "which I have here is known as a canula, a little canal, for leading off blood from the veins of one person to another—in other words, blood transfusion. Modern doctors are proving themselves quite successful in its use.
"Of course, like everything, it has its own peculiar dangers. But the one point I wish to make is this: In the selection of a donor for transfusion, people fall into definite groups. Tests of blood must be made first to see whether it 'agglutinates,' and in this re-
