626 



SCIENCE 



[Vol. LV, No. 1432 



purposes of strict accuracy, therefore, the acid 

 should be added to normal saline or Ringer's 

 solution, but for class purposes the distilled 

 water will serve. 



The experiment has been designed not only 

 to show the stopping of ciliary action at a 

 definite hydrogen-ion concentration, but also to 

 bring out the difference in effect between an 

 organic acid, such as acetic, and a mineral acid, 

 such as hydrochloric. In the latter case even 

 a concentration, p^ = 2, thymol blue as indi- 

 cator, will not stop the beating of the cilia in 

 less than 15 minutes. The gi-eater concentra- 

 tion of hydrogen-ion required for the mineral 

 acid than for the organic acid is of course cor- 

 related with the difference in rate of penetra- 

 tion of these acids into tissues. 



Furthermore, in order to obtain comparable 

 results the pieces of epithelium must be from 

 corresponding regions of the frog. If the 

 tissue is taken from the more posterior levels, 

 i. e., from within the esophagus itself, where 

 the cilia are very long, it is found that the 

 beating continues for a longer time in a given 

 concentration of acid than in the pieces from 

 more anterior levels, i. e., the back of the 

 mouth, where the cilia are very short. The ex- 

 periment therefore brings out the fact that sus- 

 ceptibility to acid decreases in passing from 

 anterior to posterior levels of the alimentary 



tract. 



J. M. D. Olmsted 



J. W. MacAethur 

 IJNrvEESiTT OP Toronto 



Reference: "W. M. Clark, 1920, The Determina- 

 tion of Sydrogen-Ions. 



THE SOCIETY OF MAMMALOGISTS 



The fourth annual meeting of the Society of 

 Mammalogists was held in New York City on 

 May 16 to 18, 1922, where the society was 

 invited to hold its meetings at the American 

 Museum of Natural History. Besides the reg- 

 ular business sessions and the election of new 

 officers, papers were presented, and the pro- 

 gram is given as follows : 



Tuesday, Mat 16 

 Afternoon Session, 2:00 P.M. 

 The present status of the elk: E. A. Goldman. 

 Mammals of the mountain tops: WiLLLiM L. 



FiNLEY. (Presented by John Treadwell Nichols). 



The water supply of desert mamjnals: Vernon 

 Bailey. 



A quantitative determination of damage to 

 forage by the prairie-dog, oynomys gunnisoni 

 zuniensis Hollister: Walter P. Taylor. 



Studies of the Yellowstone wild life hy the 

 Soosevelt Station: Charles C. Adams. 



The part played by mammals in the World War : 

 Ernest Harold Baynes. 



Evening Session, 8:00 P.M. 

 The members of the society were invited to the 

 new home of the Explorers' Club, 47 West 76th 

 Street. The board of directors of the club ex- 

 tended the courtesy of the club to the members of 

 the society during their session. 



Wednesday, May 17 

 Morning Session, 10:00 A.M. 



The frequency and significance of bregmatie 

 fontanelle bones in mammals: Adolph H. 

 Schultz. 



A fossil dugong from Florida: Glover M. 

 Allen. 



Certain glands in the dog tribe: Ernest 

 Thompson Seton. 



The elephant in captivity: W. H. Sheak. 



The burrowing rodents of California as agents, 

 in soil formation: J. Grinnell. 



Afternoon Session, 2:00 P.M. 



Symposium on the Acatomy and Relationships 

 of the Gorilla: 



Bow near is the relationship of the gorilla- 

 chimpanzee stoclc to man? W. K. Gregory. 



Notes on the comparative anatomy of the 

 gorilla: G. S. Huntington. 



Was the human foot derived from a gorilloid 

 type? D. J. Morton. 



Beiohenow's observations on gorilla behavior: 

 J. H. McGregor. 



On the sequence of eruption of permanent 

 teeth in gorilla and man: MiLO Hellman. 



Phylogenetic relations of the gorilla: evidence 

 from brain structure: Frederick Tilney. 



Evening Session, 8:00 P.M. 



The motion picture as a medium for intimate 

 animal studies: Arthur H. Fisher. 



Motion pictures, some showing slow motion, of 

 anthropoidea, sea lion, Barbary sheep, kangaroo 

 and yak, and the habits of the beaver: Raymond 



L. DiTMARS. 



Motion pictures of sea-elephants: Charles H. 

 Townsend. 



