All who have used direct methods in examining scales from the palms and soles for the presence of fungi have not infrequently been disconcerted by finding the mosaic fungus. It is a form that assumes geometric figures that trace the outlines of the cells in the scale. The mosaic material does not cross the body of the cells but always remains at their periphery.
Weidman,1 who gave this form its name, had this to say about it:
. . . the segments are irregularly shaped, and are separated from each other by narrower or broader, but definite, spaces; they have a moth-eaten appearance, and their edges and corners are rounded off. They do not have any organized internal structure; arthrospores are not visible within the segments. But it is the arrangement of the mycelium that raises the question whether this is fungus—not so much that it occurs in smaller and larger