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Index Medicus: A monthly classified record of the current medical 

 literature of the world. Second Series. Edited by Robert Flet- 

 cher, M. D., and Fielding H. Garrison, M.D. Subscription price, 

 five dollars per annum in the United States, Canada and Mexico, 

 with 60 cents additional for postage to other countries. 



Year Book No. I, 1902. Octavo, 351 pages. Out of print. 



Year Book No. 2, 1903. Octavo, 371 pages. Out of print. 



Year Book No. 3, 1904. Octavo, 305 pages, 6 plates. Ji. 



Year Book No. 4, 1905. Octavo, VIII + 3O3 pages, 7 plates. Ji. 



No. I. The Carnegie Institution of Washington, D. C. Octavo, 16 

 pages. Out of print. 



No. 2. Articles of Incorporation, Deed of Trust, etc. Octavo, 15 

 pages. Out of print. 



No. 3. Proceedings of Board of Trustees. Octavo, 15 pages. Out 

 of print. 

 [The matter contained iii Nos. i, 2, and 3 is embodied in Year Book No. I.] 



No. 4. The Waterlilies : A monograph of the Genus Nymphaea. 

 By Henry S. Conard. Quarto, xin + 279 pages, 82 text 

 figures, 30 plates, including 12 plates colored to life. $6.50. 



No. 5. Catalogue of Double Stars. By S. W. Buruham. Quarto. 

 In press. 



No. 6. Desert Botanical Laboratory of Carnegie Institution. By 



F. V. Coville and D. T. MacDougal. Octavo, VI + 58 pages, 29 



plates. 50 cents. 

 No. 7. New Method for Determining Compressibility. By T. W. 



Richards and W. N. Stull. Octavo, 45 pages, 5 figs. 25 cents. 

 No. 8. Bibliographic Index of North American Fungi. By W. G. 



Farlow. Octavo. Vol. I, part I, xxxv + 312 pages. $2. 

 No. 9. The Collected Mathematical Works of G. W. Hill. Quarto, 



4 vols. Vol. i, xvin + 363 pages; Vol. 2, vn+339 pages; Vol. 3, 



577 pages. $2.50 per volume. Vol. 4 in press. 

 No. 10. Contributions to Stellar Statistics. On the Position of the 



Galactic and Other Principal Planes Toward Which the Stars 



Tend to Crowd. By Simon Newcomb. Quarto, 30 pages. 25 cents. 

 No. II. A Statistical Inquiry into the Probability of Causes of the 



Production of Sex in Human Offspring. By Simon Newcomb. 



Octavo, 34 pages. 25 cents. 

 No. 12. The Action of Snake Venom upon Cold-blooded Animals. 



By Hideyo Nognchl. Octavo, 16 pages. 25 cents. 



43 



:ial in character, is clearly 

 middle, and inmost. In 

 essed oblong, therefore, 

 ley are large and diffuse ; 

 he basement membrane, 

 lial sinus, gs, the tissue of 

 interspersed with plasma 

 issed through the special- 

 ay be assumed that the 

 us the closely compacted 

 plasma spaces (and capil- 

 hese again transfer their 

 1 the egg. 



33C 



) mm. in diameter), gy. Germinal 

 oup of chromosomes ; mgT, limiting 



region of the zona radiata. In this 



. vesicle recedes from surface of egg. 

 c, showing large vacuoles ; :, zona 

 n the vesicle and the adjacent tunic 



rently physiological, since 

 :leus of the inmost layer 

 is clearly connected with a nucleus ot the middle layer. ~In some cases such a rela- 

 tionship is demonstrated by dividing nuclei, which, it may be remarked, exhibit 

 sometimes direct, sometimes indirect division. At the surface of the egg is a sharply 

 marked membrana limitans ; below this, irregular in thickness, a zona radiata, prob- 

 ably homologous with the well-known layer in eggs of other fishes. Below this the 

 egg shows an outer finer layer and an inner coarser or reticular layer, in which 

 large vacuoles frequently occur. At a somewhat later stage (egg measuring about 



