I have found it as you predicted a matter of considerable difficulty to find the mature forms of the Gemiasmas in the blood, but the spore forms of the vegetation I have no difficulty in finding. The spores have appeared to me to be larger than the spores of other vegetations that grow in the blood. They are not capable of complete identification unless they are cultivated to the full form. They are the so-called bacteria of the writers of the day. They can be compared with the spores of the vegetation found outside of the body in the swamps and bogs. You said that the plants are only found as a general rule in the blood of old cases, or in the acute, well marked cases. The plants are so few, you said, that it was difficult to encounter them sometimes. So also of those who have had the ague badly and got well. Observation at Naval Hospital, N.Y., Aug., 1877. Examined with great care the blood of Donovan, who had had intermittent fever badly. Negative result. The same was the result of examining another case of typho-malarial (convalescent); though in this man's blood there were found some oval and sometimes round bodies like empty Gemiasmas, 1/1000 inch in diameter. But they had no well marked double outline. There were no forms found in the urine of this patient. In another case (Donovan,) who six months previous had had Panama fever, and had well nigh recovered, I found no spores or sporangia. Observations made at Washington, D.C., Sept., 1879. At this time I examined with clinical microscope the blood of eight to ten persons living near the Congressional Cemetery and in the Arsenal grounds. I was successful in finding the plants in the blood of five or more persons who were or had been suffering from the intermittent fever. In 1877, at the Naval Hospital, Chelsea, I accidentally came across three well marked and well defined Gemiasmas in the blood of a marine whom I was studying for another disease. I learned that he had had intermittent fever not long before. Another positive case came to my notice in connection with micrographic work the past summer. The artist was a physician residing in one of the suburban cities of New York. I had demonstrated to him Gemiasma verdans, showed how to collect them from the soil in my boxes. And he had made outline drawings also, for the purposes of more perfectly completing his drawings. I gave him some of the Gemiasmas between a slide and cover, and also some of the earth containing the soil. He carried them home. It so happened that a brother physician came to his house while he was at work upon the drawings. My artist showed his friend the plants I had collected, then the plants he collected himself from the earth, and then he called his daughter, a young lady, and took a drop of blood from her finger. The first specimen contained several of the Gemiasmas. The demonstration, coming after the previous demonstrations, carried a conviction that it otherwise would not have had.