September 6, 1906] 



NA TURE 



483 



iraiisniitling sliiiuili, ;iikI capable o( isolated paralysis, ami 

 also of a substance or substances concerned with the main 

 function of the cell (contraction or secretion, or in the case 

 of nerve cells of discharging nerve impulses). So far as 

 this is concerned, it does but accentuate a view which has 

 often been put forward, and which, indeed, in some form 

 or other is inseparable from the idea of protoplasm. 



The author had spoken of different " substances " in the 

 cell with the intent to use as vague a term as possible. 

 The "substances," he took it, are radicles of the proto- 

 plasinic molecule ; at present, however, he did not think 

 it advisable to speculate further, either on this question or 

 on certain other questions raised by the conclusions arrived 

 at in the paper. There are a number of obvious experi- 

 ments still to be made, and these, it may be hoped, will 

 settle some of the problems, the solution of which is now 

 but guesswork. 



June 14. — " The Experimental Analysis of the Growth 

 <.f Cancer." By E. I'. Bashford, J. A. Murray, and 

 W. II. Bowen, 



I'he proliferation of Jensen's tumour when propagated 

 ill large numbers of mice is not uniformly progressive, but 

 presents fluctuations which can be referred, with confi- 

 dence, to the tumour cells themselves. The experimental 

 conditions which introduce irregularities are shown to be 

 (i) differences in race of the mice used, e.g. tame or wild; 

 (2) differences in age of mice even of the same kind — 

 voung animals are measurably more suitable than adult 

 animals ; (3) the site of implantation of the cellular graft — 

 the subcutaneous tissue of the back was found to be more 

 suitable than, for example, the peritoneal cavity ; (4) the 

 size of the graft was found to be of importance, but mainly 

 as modifying the apparent rate of growth ; large grafts of 

 more than O'l gram, however, were less successful than 

 -;maller ones of from o-oi gram to 002 gram, as previously 

 shown by Jensen ; (5) the mode of introduction influences 

 the success of the experiments, transplantation of small 

 fragments of unaltered tumour giving better results than 

 the injection of a suspension of tumour cells in physio- 

 logical salt solution. 



'.Artificial propagation was carried out on a large scale 

 for a long period by transplantation of grafts of from 

 o.oi gram to 002 gram of unaltered tumour into the 

 dorsal subcutaneous tissue of young tame mice from five 

 to seven weeks old. Each tumour was transplanted into 

 forty or more mice, and the results compared by estimating 

 the percentage of success on the number of animals remain- 

 ing alive after ten days. The method adopted results in 

 the separation in a large number of animals of the de- 

 -lendants of cells previously living in one animal, so that 

 .-ifter two or three successive transplantations the whole of 

 ihc tumour in one animal represents the offspring of a 

 very small part of a preceding tumour, and in the limit 

 the progenv of a single cell in a tumour more or less re- 

 mote. The percentage of success obtained with any tumour 

 is used as an indication of the frequency in it of cells 

 capable of continuing growth, and the results at different 

 times and with a number of propagated tumours are com- 

 pared by means of graphic records. The dates of trans- 

 plantation are measured as abscissa; and the percentages 

 of success as ordinates. Several such graphic records 

 illustrate the paper, and show that the percentage of success 

 does not vary irregularly, but that, commencing with a 

 tumour giving a low percentage, successive transplant- 

 ations may be more and more successful until a maximum 

 is reached, it may be at 60 per cent., at 70 per cent., or 

 at 100 per cent. The subsequent transplantations are not 

 so successful. The percentage of success falls rapidly either 

 at the first essay or in two or more steps until a minimum 

 is reached, after which the process is repeated. It is con- 

 cluded that the tumour cells present a cyclical activity, and 

 suggested that the period of lower percentage of success 

 represents a faiiure of the proliferative powers from which 

 recovery occurs when the transplantations show again a 

 progressively higher percentage of success. A graphic 

 record of the behaviour of a large number of separate 

 strains shows a continuously high maximum of success 

 between 70 per cent, and qo per cent, due to the .suc- 

 cessive development of maxima in separate strains, and it 

 is suggested that sporadic tumours possess a siiiiilar com- 



NO. 1923, VOL. 74] 



plexity, so that growth may be proceeding rapidly at one 

 part while dying out at another. 



Spontaneous absorption of well-established tumours 

 occurred at the same time as the rapid fall in percentage 

 of success, failure of the cells to establish themselves in 

 new animals coinciding with cessation of growth and 

 extinction in animals in which they had been able to grow 

 for a time. Without prejudice to other factors, it may be 

 presumed that the greater frequency of spontaneous 

 absorption in transplanted tumours may be due to their 

 greater homogeneity resulting from the repealed inter- 

 calation of what is virtually a unicellular stage. 



The extinction of certain strains of Jensen's tumour is 

 alluded to and compared with the results of transplanting 

 two other spontaneous mouse carcinomata, which after 

 successful transference to normal animals gave pro- 

 gressively lower percentages of success until negative results 

 were obtained. 



The results indicate the necessity for caution in interpret- 

 ing experiments designed to modify the growth of pro- 

 pagated tumours, and for accurate records of their previous 

 history as a necessary accompaniment to therapeutical 

 experiments. 



June 21. — " On the Electric Inductive Capacities of Dry 

 Paper and of Solid Cellulose." By .Mbert Campbell. 



June 28. — " Sex-determination in Hydalina, with some 

 Remarks on Parthenogenesis." By R. C. Punnett. 



July 12. — " .\ Method for determining Velocities of 

 Saponification." By James Walker. 



The author takes advantage of the change in electrical 

 conductivity for following the progress of the action of a 

 caustic alkali on an ester. The conductivity of the original 

 solution falls off to about one-third as the saponification 

 proceeds, and the relation between change of conductivity 

 and proportion transformed is very nearly linear. .\ 

 device is described for simplifying the calculation of the 

 velocity constant by appropriate selection of the resistance 

 in the rheostat. Readings can easily be taken every 

 minute, and the method is much less troublesome than the 

 titration method usually employed, whilst yielding equally 

 accurate results. 



Edinburgh. 

 Royal Society, Julv 16. — The Hon. I.nrd M Laren. vice- 

 president, in the chair. — Limnographic apparatus and 

 measurements on Loch Earn : Prof. Chrystal. The paper 

 gave a detailed account of the various modifications and 

 simplifications which experience had suggested during the 

 recording of seiches on the Scottish lochs. The effects of 

 friction had been reduced to a minimum, so that it was 

 possible to obtain records of short period motions such as 

 wind and other meteorological causes produce. The effect 

 of access tubes connecting the well of the limnograph 

 with the free water of the loch had been studied with 

 great care. By use of a proper sized access tube the 

 shorter disturbances could be cut off and the seiche re- 

 corded in all its purity. A new and very simple method 

 of reduction of limnograms so as to separate the various 

 orders of seiches was described. This method of " residu- 

 ation " consisted simply in superposing the seiche record 

 upon itself displaced half the uninodal period forward. 

 This eliminated the uninodal seiche and left the binodal 

 and trinodal, if such were present. .A second application 

 of the same method eliminated the binodal, and in this 

 way the principal nodalities could be separated with great 

 ease and accuracy. It was impossible to apply harmonic 

 analysis to seiches simplv because there was no harmonic 

 relation ainong the periods of the various nodalities. — Pre- 

 liminary limnographic observations on Loch Earn : Mr. 

 James Murray. This paper .supplemented the previous 

 paper, and described the difficulties encountered in measur- 

 ing the seiches by the forms of apparatus devised by Prof. 

 Chrystal. For eye observations the portable seismoscope 

 had been found very serviceable. It could be installed and 

 taken down again in a few minutes, and packed into a 

 compass small enough to go into one's pocket. — .\ note on 

 the polarimeter : j. R. Milne. Two appliances were 

 described. The first, which consists of a thin plate of 

 glass placed obliquely across half the beam of light pass- 

 ing through the instrument, gives the slight rotation of 



