while all received their higher training, especially in the languages, from their father. The boys aided in the farming operations and Theodore early manifested a marked interest in the natural sciences, and especially in botany; in which, however, his father could not help him. He soon found an enthusiastic helper in his younger brother Eugene, and together they made extensive collections of the native plants and insects of the vicinity. Dr. George Engelmann, a second cousin, greatly assisted the boys in their botanical studies.
Early in 1847 Theodore went to Europe and entered the University of Heidelberg as a student of medicine. Henle, Chelius and Hasse then made Heidelberg the most notable center for medical study outside of Vienna, while Bischoff represented botany. Hilgard at once began to make what subsequently became a very complete collection of the flora of central Europe. The revolutionary agitation of 1848 somewhat 
Fig. 12. Dr. Theodore C. Hilgard; by courtesy of Dr. Eugene Hilgard. disturbed the regularity of the course of study, but no actual interruption occurred until, in the spring of 1849, active revolutionary movements took place in Baden itself. Theodore then (with his brother Eugene, who had meantime joined him) went to Zürich, and there passed three semesters, studying especially microscopy under Naegeli, and physiology under Ludwig, besides attending the natural history lectures of Oken. During this time the brothers made extended excursions on foot through Switzerland and collected the Alpine flora. In 1851 Theodore went to Vienna to study, where were then such medical celebrities as as Rokitansky, Oppolzer, Bednar and Hebra. After nearly two semesters, during which he gave much time to botanical study in the great Endlicher collection, he was obliged to go to Malaga to bring back his widowed sister. While there he made an extensive collection of Mediterranean plants which greatly interested him. On his return he went to Würzburg, where he graduated in June, 1852, summa cum laude, as doctor in medicine, surgery and obstetrics. He then went to Berlin to study ophthalmology with Graefe, as well as surgery. In the summer of 1853 he returned to America, taking a position as ship physician on an emigrant vessel, on which he experienced an epidemic of cholera.
