Complex sentence: He began the study of medicine at Erlangen in 1822, and finished his curriculum in 1826 at Würzburg, where he had attached himself mostly to JL Schönlein in medicine and to Karl Friedrich Heusinger in comparative anatomy.
Split into simpler sentences: He began the study of medicine at Erlangen in 1822. Wagner completed his curriculum in 1826 at Würzburg, where he mainly studied under JL Schönlein in medicine and to Karl Friedrich Heusinger in comparative anatomy.