REPORT OF THE PRESIDENT, 1920. 27 



Castle, W. E. The measurement of linkage. Amer. Nat., vol. 54, 264-267 (May 1920). 



. Linked genes in rabbits. Science, n. s., vol. 52, 156, 157 (Aug. 13, 1920). 



Chow, Ming. Free energy of potassium hydroxide in aqueous solution and the activities of its 



ions. Jour. Amer. Chem. Soc, vol. 42, 488-497 (Mar. 1920). 

 . Activities of the ions in solutions of mixed electrolytes. Jour. Amer. Chem. Soc, vol. 



42, 497-502 (Mar. 1920). 

 Coble, Arthur B. The ten nodes of the rational sextic and the Cayley symmetroid. Amer. 



Jour. Math., vol. 41. No. 4, 243-265 (Oct. 1919). 

 Collins, W. E. See Benedict, Francis G. 

 Corner, George W. On abnormalities of the pig embryo occurring before attachment to the 



uterus. Anat. Rec, vol. 18, 229 (1920). 

 Cunningham, R. S. The reaction of peritoneal mesothelium to granular suspensions and laked 



blood. Anat. Rec, vol. 18, 229 (1920). 

 Cushman, J. A. Observations on living specimens of Iridio diaphana, a species of Foraminifera. 



Proc U. S. Nat. Mus., vol. 57. 153-158, pis. 19-21 (1920). 

 Daniels, F. See Richards, T. W. 

 Davenport, C. B. A strain producing multiple births. Jour. Hered., vol. 10, 382-384 (Nov. 



1919). 

 . Influence of the male in the production of twins. (Reprint.) Med. Rec, vol. 97, 



509-511. (Mar. 27, 1920). 

 -. Influence of the male in the production of human twins. Amer. Nat., vol. 54, 122-129 



(Mar. 1920). 



— . Heredity of twin births. Proc. Soc. Exper. Biol, and Med., vol. 17, 75-77 (1920). 

 See Love, A. G.; Ritzman, E. G. 



Davis, Carl L. The relation of the somites of the head to the brain in a human embryo of 



twenty paired somites. Anat. Rec, vol. 18, 232 (1920). 

 Davis, Helen N. See Shapley, Harlow. 

 Day, Arthur L. Optical glass and its future as an American industry. (Papers on Optical 



Glass, No. 26.) Jour. Franklin Inst., vol. 190, 453-472 (1920). 



. Memorial of George Ferdinand Becker. Bull. Geol. Soc. Amer., vol. 31, 14-25 (1920). 



Dickinson, Roscoe G. Crystal structures of wulfenite and scheelite. Jour. Amer. Chem. 



Soc, vol. 42, 85-93 (Jan. 1920). 

 Duggar, B. M. The micro-colorimeter in the indicator method of hydrogen determination. 



Ann. Mo. Bot. Card., vol. 6, 179 (1919). 



. Some factors in research. Plant World, vol. 22, 277 (1919). 



. Hydrogen-ion concentration and the composition of nutrient solutions in relation to 



the growth of seed plants. Ann. Mo. Bot. Card., vol. 7, 1 (1920). 

 Duncan, John C. Bright nebulae and star clusters in Sagittarius and Scutum photographed 



with the 60-inch reflector. Astrophvs. Jour., vol. 51, 4-12 (1920); Mt. Wilson Contr. 



No. 177. 



. See Shapley, Harlow. 



Felton, L. D. See Weed, L. H. 



Fenner, Clarence N. The Katmai region, Alaska, and the great eruption of 1912. Jour. Geol., 



vol. 28, 569-606 (1920). 

 Ferguson, J. B. The term "inversion." Science, n. s., vol. 50, 544-546 (1919). 

 , and A. F. Buddington. The binary system dkermanite gehlenite. Amer. Jour. Sci., 



vol. 50, 131-140 (1920). 

 Ferry, Edna L. Nutrition experiments with rats: A description of methods and technic. 



Jour. Lab. and Clin. Med., vol. 5, 735-745 (1920). 



— . See Osborne, Thomas B. 



Firket, J. On the origin of germ cells in higher vertebrates. Anat. Rec, vol. IS, 309-316 (1920). 

 Fleming, J. A. Description of glass magnetogram scale used by the Department of Terrestrial 



Magnetism. Terr. Mag., vol. 24, No. 4, 154-155 (Dec. 1919). 

 , and W. F. Wallis. The construction and equipment of the Watheroo Magnetic Obser- 

 vatory. Terr. Mag., vol. 25, No. 1, 1-6, 1 pi. (Mar. 1920). 

 Freed, E. Stanley. See Noyes, A. A. 

 FusEYA, G. Solubility of mercuric oxide in sodium hydroxide solutions. Jour. Amer. Chem. 



Soc, vol. 42, 368-371 (Mar. 1920). 

 Garard, I. D. See Sherman, H. C. 

 Greenberg, J. P. An unusual case of tuberculous salpingitis. Johns Hopkins Hosp. Bull., vol. 



31, 132-133 (1920). 

 GovER, Mary. See Banta, A. M. 



Hale, George E. Preliminary results of a comparative test of the 60-inch and 100-inch tele- 

 scopes of the Mount Wilson Observatory. Pubs. A. S. P., vol. 31, 257-260 (1920). 



. Lunar photography with the Hooker telescope. Pubs. A. S. P., vol. 32, 112-1 15 (1920). 



. Photographs taken with the 100-inch reflector of the Mount Wilson Observatory. 



Monthly Notices, vol. SO, 240-243 (1920). 



