On a sheet of drawings in the Uffizi, which characteristically combines with sketches of men’s heads studies of machinery, we read “This day I began the two Virgin Marys.” The day is effaced, but it is a month in 1478, ending in _-bre_—September, October or November. One of these Madonnas is, no doubt, the Madonna of the Flower.[52] As to the other we have no certainty, but the sketches of this time show at least five madonnas in process of invention. A Madonna holding a mischievous Child who hugs a writhing cat, a Madonna with a Dish of Fruit, a Madonna kneeling before the Child, a theme later developed into the Madonna of the Rocks; a Madonna seated on the Ground, and a Madonna seated in the open with the Christchild and St. John. Dr. Jens Thys thinks the last composition may be the one actually begun as a picture, since such early Raphaels as the Belle Jardinière seem to imply such a picture as their model. We do well to turn from such speculations to the marvelous sketches for these Madonnas, Figure 150. Nothing firmer, lighter or more charming can be imagined. Of the line, thinned to a hair or widened to a blot, there is the completest control. These little figures, a couple of inches high at the most and often of thumb-nail minuteness, may be enlarged to life size without losing in structure or character. Nothing shows better the sheer fecund genius of Leonardo than these sheets, crowded with figures, scribbled with his right-to-left handwriting, and slantingly shaded from upper left downwards, after the fashion of a lefthanded draughtsman. They show how Leonardo worked in spurts of inspiration, creating a dozen lovely compositions and contented with none. They represent so many tensely joyous half-hours, with doubtless long intervals of other activities and withal of sheer brooding and unrecorded observation. They help one grasp the spasmodic and discontinuous quality of Leonardo’s genius—why the actual execution of pictures was ever a matter of pain and drudgery to him. Up to his twenty-ninth year he apparently made no prolonged effort of any sort, but spent himself furiously in separate investigations. Then he pulled himself together for a great picture, and though it too never got beyond the underpainting, it broke the new path to the Golden Age.