' Record. xxxvii 



somatic cells living under special conditions, the proof has been sup- 

 plied — as much as that can be done — that ordinary somatic cells are 

 potentially immortal. He also pointed out that this conclusion could 

 still further be confirmed by serial transplantations of ordinary tissues 

 in animals of various ages. He began such experiments a number of 

 years ago and is continuing this work now under more favorable con- 

 ditions. 



Experimental tumor investigation has furthermore demonstrated that 

 many somatic cells haA'e a potential power to proliferate, which ap- 

 peared almost unthinkable until recent years. One single epithelial or 

 connective tissue cell being potentially able to produce masses of cells 

 which surpass many times the number of cells composing a whole an- 

 imal of the same species. 



Germ cells show definite rhythms. Certain Protozoa also possess defi- 

 nite rhythms, as shown by Maupas, R. Hertwig, Calkins and others. 

 Bashford and Calkins maintained that tumors also possessed definite 

 rhythmic changes. Investigations carried out by M. S. Fleisher in our 

 laboratory show such rhythms do not exist in the case of tumors. If 

 they exist in the case of other somatic tissues, they are not primary 

 attributes of these tissues, but due to secondary mechanisms. 



The death of Mr. Gilbert G. Morrison was announced. 



March 3, 1913. 



President Engler in the chair; attendance 43. 



The following donations to the Library were reported : 



LeRoy McMaster. .Two pamphlets on the preparation of ammonium 

 salts of organic acids. 



Professor F. E. Nipher gave some further observa- 

 tions on the behavior of the magnetic needle on windy and 

 calm days. 



Dr. R. A. Hall spoke on the '^ Fixation of Atmosperic 

 Nitrogen. ' ' 



Dr. R. J. Terry gave some of the results of his study 

 of ' ' The Development of the Cranium in Mammals. II. ' ' 



Dr. Terry stated that Weiss's study of the occipital region of embryos 

 of white rats revealed the fact that the dens epistrophei in these ani- 

 mals is composed of two elements, the one generally recognized as com- 

 parable with a centrum for the atlas, the other lying cephalad of this 

 and forming the extremity of the dens. The latter is derived by inde- 

 pendent chondrification in the tissue about the notochord cephalad of 

 the atlas and where the former crosses the dorsal surface of the basal 

 plate of the cranium. Weiss regarded this cephalic element as repre- 

 senting the centrum of an occipital vertebra or a proatlas. 



