A little incident that has been preserved for us by Henle shows how much his young contemporaries appreciated even at that early date, long before the full significance of the cell theory could be realized, the aspect of Schwann's work which was to make him immortal. At a little farewell dinner given him by his co-workers in various laboratories of the University of Berlin the feature of the occasion was a punning poem, by the toast-master, on the words Louvain and cells. In German Louvain is Löwen, which also means lion; that is, it is the dative case of the name of the lion. Reference is made to the fact that as Samson found honeycomb (in German, bee-cells) in the lion, so now Louvain--_i.e._, in German, Löwen, the lion--finds a champion in the man of the cells. As Samson's riddle was suggested by finding the bee-cells, so will the new professor at Louvain solve the riddles of science by the demonstration of cells. The youthful jesting seer prophesied better than he knew. Schwann's first completed work at Louvain was the _Microscopical Researches into the Accordance in Structure and Growth of Plants and Animals._ [Footnote 11] {265} The theory it advanced was to prove the most potent element thus far introduced into biological science to help in the solution of the difficult problems that constantly occur in the study of the various forms of life. [Footnote 11: Mikroskopische Untersuchung über die Uebereinstimmung in der Structur und dem Wachsthum der Thiere und Pflanzen, 1839.] At Louvain, Schwann remained for about ten years. The period is marked by a continuance of his fruitful investigation of cell-life, of the physiological biology of ferments and fermentation, and of the allied subject of digestion in animals. His researches in Berlin on this interesting and important subject, which was practically a complete mystery at that time, had been mainly concerned with the gastric juice. He now began the study of various secretions which aid intestinal digestion. He proved that bile, which used to be considered an excretion, was really an important digestive secretion. He was not able to demonstrate the function of bile as completely as he had done for the gastric juice. The problem of intestinal digestion is much more complicated than that of stomach digestion, and involves a number of factors for which allowance has to be made if the value of any one of them is to be accurately determined. Even in our own day all of the physiological problems in the functions of biliary secretion are not solved. The greatest step was the demonstration that bile is a thing whose presence in the intestines is to be encouraged, not because, as Horace said, mental trouble was imminent unless one were purged of black bile in the springtime, but because its presence insures the proper preparation of food, and neutralizes in the intestinal tract certain poisonous substances that if absorbed would prove sources of irritation to all higher tissues.