There may be times when legislative action is so obviously dependent upon contemporary circumstances, or when its roots lie so near the chronological surface, that no study of background is possible or necessary. Such is not the case, however, with anything relating to mortgage law; it is too deeply imbedded in our legal system. And though its history be familiar it is felt that a brief review will not be out of place in considering a comparatively recent Michigan statute authorizing the assignment of rents and profits.