The true art of dancing is entirely free from all apparent effort. No matter how difficult may be the feat that is accomplished, it must seem easy. Every gesture must be expressive, every movement must be beautiful, every step must have ease and lightness and grace. Forty years ago and more, the 'Black Crook' brought to America three or four dancers trained in the best schools of Europe--Bonfanti and Betty Rigl, Rita Sangalli and Morlacchi. One of this quartet, Rita Sangalli, was afterward the chief dancer at the Paris Opéra, where she was followed in time by Rosita Mauri, a dancer who added beauty of face and of form to a masterly accomplishment. They were all gifted pantomimists; they had all of them the perfection of technic; they were all of them capable of the most varied difficulties of the art; and they all of them vanquished these difficulties with unobtrusive ease. They had attained to that perfection of art, when the art itself is hidden, and when only the consummate result is visible. Each of them had absolute certainty of execution, and each of them could float across the stage the embodiment of grace, exquisite in its ethereal delicacy. For those whose memories cannot recall the haunting remembrance of the days that are gone there is abundant compensation in the opportunity which has been afforded of late to behold the dancing of Mlle. Genée and of Mlle. Pavlova. They are, at least, the equal of any of their predecessors, and it may be doubted whether Taglioni or Fanny Elssler surpassed them in mastery. They are the perfection of effortless ease; altho they suggest only the lightness of the butterfly, they have the steel strength of the gymnast. Behind their marvelous and bewildering accomplishment there is a native gift, rich and full; and there is also the utmost rigor and perseverance in training. What they are able to do with seeming spontaneity and with apparent freedom is the result of indefatigable industry and of merciless labor. But tho this schooling sustains them, it is never paraded--indeed, it is scarcely perceived. There is not the faintest suggestion of hard work about their performances; there is nothing that hints at effort; their art is able to conceal itself absolutely, and to delight us only with the perfect result of their long apprenticeship. Capable of the most obstinate feats of strength and of agility, Mlle. Genée and Mlle. Pavlova never "show off"; they are never guilty of parading a difficulty for its own sake, and their conquest of technical obstacles serves only to support and intensify the continuous suggestion of aerial elevation and of ineffable lightness. It is to be noted, also, that as they scorn the task of the mere gymnast, they do not wear the scant costume of the acrobat; they are enveloped in ample draperies, which fall into lines of beauty with every movement.