This chapter would not be complete without some reference to that large class of women travelers who, directly or indirectly, have contributed so much to the advancement of the natural sciences. The gifted Roumanian writer and traveler, Princess Helena Kolzoff Massalsky,--better known under her pseudonym, Doria d'Istria,--somewhere expresses the opinion that a woman traveler admirably supplements the scientific work of the male explorer by bringing to it aptitudes that the latter does not possess. For she notes many things in nature, as well as in the national life and popular customs of the countries which she traverses, which escape the more hebetudinous perceptions of men, and thus a vast field, that would otherwise remain unknown, is opened to observation and critical study. One of the most noted travelers of her sex in the nineteenth century was the famous Ida Pfeiffer, of Austria. During the years intervening between 1842 and 1858, the date of her death, she traveled nearly two hundred thousand miles and, in so doing, visited nearly every quarter of the globe. When one recalls the difficulties and discomforts of transportation in the early part of the last century, as compared with our present facilities and conveniences, and bears in mind the fact that her traveling expenses for an entire year were less than those of a Lamartine or a Chateaubriand for a single week, we must admit that her achievements were, indeed, extraordinary. Besides being the author of numerous books which had for many years a great vogue--books which, by reason of the keen observations and the absolutely truthful narratives of their author, are still of special value to the student of geography and ethnology--she made collections illustrative of botany, mineralogy and entomology which were subsequently secured for the British Museum and other similar institutions in Europe. No one more highly appreciated Frau Pfeiffer's efforts in behalf of science than did the illustrious Alexander von Humboldt, whose friendship was one of the greatest joys of this remarkable woman's life. Through his recommendation and that of the noted geographer, Karl Ritter, she was made an honorary member of the Geographical Society of Berlin. Besides this, the King of Prussia conferred on her the gold medal for arts and sciences. Three other women, all representatives of Great Britain, likewise deserve notice for their extensive travels and the interesting and instructive accounts which they published of them. These are Constance Gordon Cumming, Isabella Bird Bishop and Amelia B. Edwards. More notable in many respects than these three distinguished women were Miss Mary H. Kingsley and Madame Octavie Coudreau. For their contributions to science and for their daring adventures in savage lands, they have won for themselves an unique position among women explorers.