In trying to solve the difficult question which part of the extant _oeuvre_ is Hubert's and which is Jan's, our knowledge of Jan's journeys to the South assumes considerable importance. For Hubert's travels we lack proof--they are mere conjecture. But there is documentary evidence of Jan's journey to Portugal in 1428, in addition to which Mr. Weale has, I understand, recently unearthed some further documents which establish another and earlier journey of Jan to Spain. On these travels Jan must have become well acquainted with certain plants peculiar to the South, and especially the dwarf palm or palmetto, which is confined almost exclusively to Spain and Portugal. It is therefore not unreasonable to assign to him those {33} portions of the disputed pictures in which this palmetto appears. Some authorities hold that Jan did not have any independent artistic career before Hubert's death, and that in the division of labour Hubert's share was, as a rule, the general design and the painting of the figures, whilst Jan filled in the landscape and architectural backgrounds. The collaboration theory has been advanced by Mr. A. Marks, whose knowledge of Flemish art is profound, and whose deductions are as conscientious as they are convincing. To him we are indebted for an interesting paper upon the subject, which is at once exhaustive and reasonable. To retail all that Mr. Marks advances in support of his theory would be to reprint his treatise _in toto_; but though it is impossible here to follow all his arguments, it is equally impossible to avoid reference to the valuable correspondence between him and Mr. James Weale in the _Athenæum_, between November, 1902, and April, 1903. This correspondence arose from an article by Mr. A. Marks in the _Athenæum_ in May, 1900, in which attention is drawn to the presence of the palmetto in the picture of _St. Francis receiving the Stigmata_ (now in possession of {34} Mr. J. G. Johnson, Pennsylvania; a copy in Turin), which picture had been formerly variously ascribed to Henri met de Bles, Joachim Patinier, and Mostaert. Mr. Marks has since supplemented and explained his views in the essay mentioned; whilst Miss Frances Weale has published an excellent study on the "van Eycks," which, in a concise and interesting form, presents her father's views on the subject.