24 THE AMERICAN MONTHLY. [January 



NOTICES OF BOOKS. 



The Evolution of Sex. By Prof. Geddes and J. Arthur Thompson. 



The Hiimboldt Publishing Co., 28 Lafayette Place, New York. 



Such a work as this, written by Prof. Geddes, who has contributed 

 many articles on the same and kindred subjects to the Encyclopedia 

 Britannica., and by Mr. J. Arthur Thompson, is not for the sjDccial- 

 ist, though the specialist may find it good reading, nor for the reader 

 of light literature, though the latter would do well to grapple with it. 

 Those who have followed Darwin, Wallace, Huxley, and Haeckel in 

 their various publications, and have heard of the later arguments 

 against heredity brought forward by Prof Weissman, will not be likely 

 to put it down unread. The authors have some interesting ideas to 

 state, particularly with regard to the great questions of sex and environ- 

 ment in their relation to the growth of life on earth. 



SUBSCRIBERS' NOTICES. 



[These notices will be given six insertions in this column at 25 cents per line or fraction thereof,] 

 WANTE",D TO PURCHASE. — Histological slides from normal tissues of mammals, prepared with 

 a view to show the size of the " Cells," in cases where the age of the animal-subject is definitely known, 

 as bearing on the question of a supposed diminution in the size of cells in aging organisms, correspond- 

 ing to a similar decrease, reported by Balbiani and Maupas in aged unicellular life. Address, 



C. A. STEPHENS' LABORATORY, Norway Lake, Maine. 



FOR SALE. — $30. I L. Schrauer raiscroscope with eye-pieces A and C ; movable glass stage and 

 double nose-piece ; cost, g6i. 



H. C. BENNETT, 256 West 1,16. St., New York City. 



FOR EXCHANGE.— Slides of selected diatoms. " D. B. WARD, Poughkeepsie, N. Y. 



OFFERED.— Diatomaceous Earth from ULah (Desert) for Histological Mounts. 



PROF. ORSON HOWARD, Salt Lake City, Utah. 



CORRESPONDENCE invited with a view to the exchange of either mounted or unmounted Oribatida 

 (British) for American species. E. BOSTOCK, Stone, Staffordshire. 



WANTED. — Any works on Microscopy not already in my Library. 



H. M. WHELPLEY, F. R. M. S., St. Louis, Mo. 



First-class Histological Slides for other good mounts ; Histological and Pathological material cut on 

 shares. S. G. SHANKS, M. D., 547 Clinton Ave., Albany, N. Y. 



FOR SALE CHEAP. — New Gundlach ^^ homogeneous-immersion objective, for ^'^ glycerine ot 

 water objective. J. M. ADAMS, Watertown, N. Y. 



FOR SALE. — Beautiful photo-micrographs of P. angulatum. Only 2"; cents each. 



J. E. BAKER, M. D., Wyoming, Ohio. 



FOR SALE OR EXCHANGE.— Mosquitoes, male and female. Price 75 cents each. Will ex- 

 change only for first-class mounts. E. W. SHARP, 2800 Richmond St., Philadelphia, Pa. 



A $5 MICROSCOPE. — Made on proper scientific principles. Magnifies 100 diameters or 10,000 

 times. For other interesting articUs send for list of Popular Scientific Specialties. 



G. S. WOOLMAN, 116 Fulton St., New York. 



SPECIAL BARGAIN in histological slides. 



WM. N. BEGGS, M. D., 2207 Sidney St., St. Louis, Mo. 



FOR SALE OR EXCHANGE.— Photo-micrographs of P. angulatum taken through Spencer's 

 A H. I., 2400 diameters. Also photo-micrographs of bacteria, diatoms, etc., 2=; cents each. Will ex- 

 hange for well-mounted slides. Dr. J. E. BAKER, Wyoming, Ohio. 



