The ancient Greeks and Romans amused themselves with witnessing the gladiatorial contests of their male slaves; but it was left for civilized America to introduce woman into the "ring" and make her show her paces on the race-course. An ungraceful figure she cuts, and a repulsive spectacle she presents; and worst of all is the havoc which she makes with her health. At the very time that these four female pedestrians were making their disgraceful exhibit in Boston, in another part of the same city lay a helpless invalid who was once as noted a "female walkist" as any of them, made hopelessly ill by the same disregard of the plainest laws of nature. The Male and the Female Brain.--But there are other important physical differences to which we must call attention. Man possesses a larger brain than woman, but she makes up the deficiency in size by superior fineness in quality. The female brain differs from the masculine organ of mentality in other particulars so marked that one who has given the subject attention can determine with perfect ease the probable sex of the owner of almost any skull which might be presented to him. This difference in the conformation of the skull is undoubtedly due to a difference in mental character, which, in turn, depends upon a difference in cerebral development. Faculties which are generally largely developed in one are usually smaller in the other, and the reverse. Vital Organs of Man and Woman.--The anatomist also observes an interesting difference in the size of the various vital organs. For example, while a woman has a heart proportionally smaller than the same organ in man, she has a larger liver. Thus, while less well fitted for severe physical exertion by less circulatory power, she has superior excretory powers. Woman Less Muscular, More Enduring.--This peculiarity of structure is perfectly harmonious with the fact which experience has established so often as to make the matter no longer a question, that woman is less fitted for severe muscular exertion than man, but possesses in a superior degree the quality known as endurance. With a less robust frame, a more delicately organized constitution, she will endure for months what would kill a robust man in as many weeks. More perfect elimination of the wastes of the body secures a higher grade of vitality. On no other hypothesis could we account for the marvelous endurance of the feminine part of the civilized portion of the human race, ground down under the heel of fashion for ages, "stayed," "corseted," "laced," and thereby distorted and deformed in a manner that would be fatal to almost any member of the masculine sex.