Arnold Syen is the first, but also the least known commentator of Hortus Malabaricus. These sketches are based upon Syen's own statements in Hortus Malabaricus, upon remarks of his botanical friends Morison, Breyne, and Hermann, and upon certain documents from the records of the Curators of Leiden University. Syen studied and took his medical degree at Leiden University. It has already been stated that Syen had Ceylonese material for study at his disposal: living plants in the Leiden botanical garden and objects in the museum. About Jan Commelin, the second commentator of Hortus Malabaricus, much more is known than about his predecessor Syen. Just as in the case of his predecessor Arnold Syen, it is not known whether Jan Commelin possessed a garden herbarium. In the Memorials of the Amsterdam garden there are no references to the making of a collection of dried plants grown in the garden.