May 8, 1903.J 



SCIENCE. 



741 



THE SOCIETY FOR EXPERIMENTAL BIOLOGY AND 

 MEDICINE. 



The third meeting of the Society for Ex- 

 perimental Biology and Medicine was held on 

 the evening of April 15, in Professor Graham 

 Lusk's laboratory at the University and Belle- 

 vue Hospital Medical College, ISTew York City. 

 Dr. S. J. Meltzer presided. 



In harmony with the aims of the society 

 the evening was devoted mainly to reports of 

 original work done by the members, with dem- 

 onstrations of methods and results. The pro- 

 gram was as follows : * - 



I. REPORTS OF ORIGINAL WORK, WITH DEMON- 

 STRATIONS. 



Changes in the Blood-volume of the Vein 

 of the Submaxillary Gland on Stimulation 

 of the Chorda Tympani and Sympathetic 

 Nerves: R. Burton-Opitz. 



Dr. Burton-Opitz explained the mechanism 

 of a recording stromuhr by means of which 

 he made quantitative determinations of the 

 blood flow in the vein conveying the blood 

 from the submaxillary gland. The blood-vol- 

 ume was measured previous to, as well as 

 during, the stimulation of the secretory nerves. 

 The curves which were exhibited showed very 

 striking changes in the blood-flow, namely, 

 an increase on stimulation of the chorda and 

 a decrease when the current was applied to 

 the sympathetic fibers. In the former case the 

 volume of the blood flow (cubic centimeters 

 per second) was from about two to nearly 

 six times as great as normal, and in the latter 

 case it was from about one half to one fifth 

 the normal volume. By using a strong stim- 

 ulus a complete cessation of flow can be pro- 

 duced. 



* The secretary has received an abstract of each 

 report from the member making it, and in editing 

 these abstracts has made only occasional verbal 

 and minor alterations in them, such as abbrevia- 

 tions and the like. The abstracts here given are 

 in fact, therefore, the contributions of the several 

 members themselves, and should be so credited. 

 This statement applies to the former report also 

 (Science, XVII., p. 468), and will be true of 

 those in the future. 



Does a Backward Plow ever occur in the 

 Vei7isf : E. Burton-Opitz. 



The results of this investigation may be 

 summarized as follows: A backward swaying 

 of the column of blood in the central veins is a 

 constant, normal phenomenon. It is produced 

 by two factors: first, by the contraction of 

 the right side of the heart, and secondly, by 

 high intra-thoracic pressure (forced expira- 

 tion). If the distal conditions in the venous 

 system are favorable, this backward move- 

 ment can also be obtained in the peripheral 

 veins (femoral vein). The same instrument 

 was used in this investigation as in the former. 



A New Method of Studying Metaholism: 

 Gary N. Calkins. 



Dr. Calkins described experiments now in 

 progress upon metabolism in unicellular ani- 

 mal organisms. These forms, reproducing 

 by simple division, offer the same protoplasm 

 for study, generation after generation, and, 

 with each division, the daughter organisms, 

 by reason of the functions of regulation and 

 regeneration, perfect themselves in the race- 

 type, while digestion, assimilation, waste, re- 

 pair and growth are handed down unchanged 

 from cell to cell. The problem is to ascertain 

 whether these various functions will continue 

 their activities indefinitely or whether proto- 

 plasmic old age will supervene to put an end 

 to the race. In nature such an end is pre- 

 vented by sexual union, whereby the conju- 

 gating organisms are rejuvenated. 



In the experiments this function was pre- 

 vented by isolation. The general metabolic 

 functions wore out four consecutive times at 

 intervals of six months, and each time, except 

 the last, the race was saved only by a change 

 in diet or by chemical stimuli. The phenom- 

 ena were analogous to those in the artificial 

 fertilization experiments of Loeb and others, 

 with this difference, that, if comparable with 

 artificial parthenogenesis, the process was re- 

 peated with the same protoplasm three con- 

 secutive times. In the fourth period of de^ 

 generation the stimuli previously tried were 

 no longer effective and the race died out, 742 

 generations old. Structural changes were 

 different in the different periods of depression. 



