I regret that I am unable to pursue this subject much further; but there is one point I should mention. In Harvey's time, the microscope was hardly invented. It is quite true that in some of his embryological researches he speaks of having made use of a hand glass; but that was the most that he seems to have known anything about, or that was accessible to him at that day. And so it came about, that, although he examined the course of the blood in many of the lower animals—watched the pulsation of the heart in shrimps, and animals of that kind—he never could put the final coping-stone on his edifice. He did not know to the day of his death, although quite clear about the fact that the arteries and the veins do communicate, how it is that they communicate—how it was that the blood of the arteries passed into the veins. One is grieved to think that the grand old man should have gone down to his tomb without the vast satisfaction it would have given to him to see what the Italian naturalist Malpighi showed only seven years later, in 1664, when he demonstrated, in a living frog, the actual passage of the blood from the ultimate ramifications of the arteries into the veins. But that absolute ocular demonstration of the truth of the views he had maintained throughout his life it was not granted to Harvey to see. What he did experience was this: that on the publication of his doctrines, they were met with the greatest possible opposition; and I have no doubt savage things were uttered in those old controversies, and that a great many people said that these new-fangled doctrines, reducing living processes to mere mechanism, would sap the foundations of religion and morality. I do not know for certain that they did, but they said things very like it. The first point was to show that Harvey's views were absolutely untrue; and not being able to succeed in that, opponents said they were not new; and not being able to succeed in that, that they didn't matter. That is the usual course with all new discoveries. But Harvey troubled himself very little about these things. He remained perfectly quiet; for although reputed a hot-tempered man, he never would have anything to do with controversy if he could help it; and he only replied to one of his antagonists after twenty years' interval, and then in the most charming spirit of candour and moderation. But he had the great satisfaction of living to see his doctrine accepted upon all sides. At the time of his death, there was not an anatomical school in Europe in which the doctrine of the circulation of the blood was not taught in the way in which Harvey had laid it down. In that respect he had a happiness which is granted to very few men.