Febbuaby 17, 1911] 



SCIENCE 



255 



which a natural suspected hybrid is known, 

 a duplicate of which Miss Slosson produced 

 culturally. Most of his experiments at cross- 

 ing were made with species in unrelated 

 genera, e. g., Pteris and Athyrium, two genera 

 belonging in entirely different tribes. Also, 

 he cites as the best evidence previous to his 

 paper the work of C. Voegler, who was unable 

 to obtain fusion between the sperms and eggs 

 of several pairs of unrelated fern genera, some 

 of them genera from very distinct families, 

 e. g., Ceratopteris and Dichsonia, Dicksonia 

 and Nephrolepis, et al. 



The case, then, for fern hybrids, stands just 

 where it did and is based on facts which re- 

 quire reasonable explanation. The evidence 

 favoring hybrids has been fully presented, and 

 does not need recapitulation. It is quite true 

 that experimental proof of the kind attempted 

 by Hoyt and Voegler is lacking. No one has 

 ever observed the development of a suspected 

 hybrid from before the period of fusion of the 

 gametes. But such evidence is not usually 

 required in cases of reputed hybridity. The 

 arguments advanced by Mr. Hoyt against fern 

 hybridity apply with practically equal force to 

 most cases of accepted hybridity among flower- 

 ing plants and in animals. 



In conclusion, then, these reputed fern hy- 

 brids possess in all respects the characters gen- 

 erally recognized as characteristic of hybrids. 

 The existence of these plants demands some 

 explanation, and their identification as hybrids 

 furnishes the simplest and most reasonable one 

 yet offered. Ealph C. Benedict 



Columbia Univebsitt 



THE AMEBICAW ASSOCIATION FOR THE 



ADVANCEMENT OF SCIENCE AND 



AFFILIATED SOCIETIES 



SECTION B— PHYSICS 



The annual meeting of the American Associa- 

 tion for the Advancement of Science, Section B, 

 Physics, was held in the physical laboratory of 

 the University of Minnesota, at Minneapolis, 

 December 28-30, 1910. It was a joint meeting 

 with the American Physical Society. Three fore- 

 noon and three afternoon sessions were held. Of 

 these, two were " general interest " sessions, in 

 charge of the officers of Section B and four were 



occupied with the reading of research papers, in 

 charge of the American Physical Society. 



The presiding officers were Dr. E. B. Rosa, vice- 

 president of Section B, and Professor Henry Crew, 

 president of the Physical Society. At a short 

 business session of Section B Professor O. M. 

 Stewart was elected a member of the council, 

 Professors A. Zeleny and K. E. Guthe members 

 of the sectional committee and Professor G. W. 

 Stewart a member of the general committee. 



All sessions were held in the lecture room of 

 the Physics Building of the University of Minne- 

 sota. The dinner on Thursday evening with the 

 mathematicians and engineers at the Commercial 

 Club was a very pleasant and enjoyable occasion. 



The officers for the next annual meeting, to be 

 held in Washington during the convocation week 

 of 1911-12, are as follows: 



Vice-president and Chairman of Section B — 

 Professor R. A. Millikan, University of Chicago. 



Retiring Vice-president — Dr. Edward B. Rosa, 

 Bureau of Standards, Washington. 



Secretary — Professor Alfred D. Cole, Ohio State 

 University, Columbus. 



Members of the Sectional Committee — E. B. 

 Rosa, R. A. Millikan, A. D. Cole, K. E. Guthe, 



A. P. Carman, G. F. Hull, E. L. Nichols, A. 

 Zeleny. 



The address of the retiring chairman of Section 



B, Dr. L. A. Bauer, was given Thursday after- 

 noon on the subject "The Broader Aspects of 

 Research in Terrestrial Magnetism." This was a 

 joint session with Section D, whose vice-presi- 

 dential address was delivered at the same time 

 by Professor J. F. Hayford, on "The Relation of 

 Isostasy to Geodesy, Geology and Geophysics." 

 The former of these addresses is presented in full 

 in Science, January 13, 1911, and the other will 

 be published soon. 



At the other general interest session the follow- 

 ing program was presented: 



"Recent Advances in Phosphorescence and 

 Fluorescence," Professor Edw. L. Nichols, Cor- 

 nell University. 



" The Isolation of Ions," Professor R. A. Milli- 

 kan, University of Chicago. 



" The International Electric Units " ( report on 

 changes to go into effect January, 1911), Dr. B. 

 B. Rosa, Bureau of Standards, Washington. 



" Osborne-Reynolds's Theory of Gravitation," 

 John Mackenzie, M.E., Minneapolis. 



Abstracts of three of these papers follow. 

 (That of Professor E. L. Nichols will probably 

 appear in the next issue.) 



