November 25, 1915] 



NATURE 



355 



irobably due to some action related to the solvent 

 loperties of urea. All attempts at synthesis of urea 

 V urease failed. Prof. Bayliss referred to the com- 

 >l<xitv of the process of hydrolysis of urea, and believes 

 hat the first action of urease on urea is to form 

 .tinmonium cyanate. The change of ammonium car- 

 amate to carbonate is not accelerated by urease. An 

 nteresting- discussion of problems raised by the paper 

 i.llowed, in which Prof. Ramsden and Prof. Moore 

 ;iH)k part. 



Dr. J. Tait gave a communication on capillary 

 phenomena in blood cells, and on phagocytosis. He 

 described the movement of the spindle-shaped cells 

 of invertebrate blood in coagulation, and pointed out 

 their analogies with blood platelets. Such cells are 

 phagocytic, but not amoeboid ; their movement is irre- 

 versible and passes into cytolysis. Dr. Tait proposes 

 the name "Thigmocyte" for this class of blood cell. 

 If the thigmocyte is unstable for any substance it is 

 phagocytic for that substance. The movement may 

 be explained physically, and obeys the laws of capil- 

 lary attraction. Leucocytes, on the other hand, may 

 be stable on a foreign substance, and yet be capable 

 of ingesting small fragments of that substance. Dr. 

 Tait showed that this is not inconsistent with a physical 

 explanation. He further proposed a physical explana- 

 tion for various blood phenomena, amu.'boid move- 

 ment, diapedesis, the relation between agglutinins and 

 opsonins, and the coagulation of blood. 



Dr. C. E. Lea showed lantern slides of electro- 

 cardiograph records from clinical cases of auricular 

 fibrillation of the heart, and pointed out the value of 

 this method as a mode of diagnosis. The action of 

 drugs on the condition was also illustrated. 



Dr. E. P. Poulton read a paper on the alleged acid 

 intoxication of diabetic coma. He analysed a series 

 of cases showing the amount of alveolar COg and 

 the hydrogen-ion in the blood. Dr. Poulton finds no 

 evidence of acid intoxication in diabetic coma ; the 

 blood, indeed, shows no increase in H-ion concentra- 

 tion in this condition, and is less acid than in uraemia, 

 or even after moderate exercise. He believes the 

 coma of diabetes to be the direct action of some 

 poison, possibly acetoacetic acid. The lowering of 

 the alveolar CO^ may be to some extent responsible, 

 and is in itself a trustworthy index to the onset of the 

 eondition. 



Prof. W. H. Thompson recorded some experiments 

 upon arginine and the formation of creatine. He *ed 

 or injected dogs and ducks with arginine, and esti- 

 mated the output of creatine. In nearly all cases 

 there was an increase of the creatine-creatinine output, 

 injection giving the higher result. Racemic arginine 

 gave no greater effect than dextro-arginine. 



Prof. Thompson also contributed a paper on the 

 efifects of tetanisation on the creatine and creatinine 

 in the muscle of the cat. A decerebrate animal was 

 used and the creatine estimated by Folin's method. 

 There was an apparent decrease as the result of long- 

 continued activity of the muscle, but Prof. Thompson 

 did not believe there was any real alteration, the 

 apparent decrease being explained by other factors. 



On Friday Dr. C. Powell White described a test 

 for copper sufficiently delicate to detect i/iooth of a 

 milligram in 15 c.c. of fluid. The test is identical 

 with Oliver's test for morphine. Dr. Powell White 

 found copper in all the tissues of the body and in 

 various foodstuffs, animal and vegetable. Quantita- 

 tive measurements were niade by the ferrocyanide 

 method. The copper may possibly play an important 

 I)art in the reactions taking place in the living cell. 



Dr. Lamb and Mr. Holker reviewed a number of 

 methods of differentiating fats and lipoids micro- 

 chemically, and showed lantern slides of tissues thus 

 treated. 



NO. 2404, VOL. 96] 



Dr. Lamb also illustrated the appearances of the 

 mucous membrane of the small intestine during fat 

 absorption, and showed differences in the columnar 

 cells according to the kind of fat that was 

 admini:^tcred. 



Dr. Sarah M. Baker propounded a new theory of 

 muscular contraction which she termed the "liquid 

 pressure theory." The theory was arrived at in con- 

 sequence of a similar explanation of the ascent of sap 

 in trees. An aeropermeable membrane, impermeable 

 to liquids but permeable to gases, is assumed to be 

 present in muscle. Carbohydrate is oxidised in the 

 muscle with the production of water and COj. The 

 formation of water causes a liquid pressure which 

 manifests itself as a contraction of the muscle. Re- 

 laxation is due to rapid evaporation of water through 

 the membrane. The heat thus lost reduces the total 

 energy of the oxidation process by about nine per 

 cent. Dr. Baker cited a number of observations sup- 

 porting various points in the theory. In the discussion 

 that followed, Prof. Thompson and Prof. Herring 

 criticised the application of this theory to muscle in 

 several details, and Dr. Baker replied. 



Dr. Tait and Dr. Harold Pringle then gave a paper 

 on the elasticity of the strophanthinised heart. 

 Tracings of an isolated frog ventricle in Schiifer's 

 plethysmograph were exhibited by the lantern, and the 

 action on it of strophanthin demonstrated. The 

 amount of relaxation of the ventricle was shown to be 

 directly proportional to the preceding contraction, and 

 to be entirely due to the elasticity of the heart. 



BOTANY AT THE BRITISH 

 ASSOCIATION. 



'X*HE meeting this year was a busy and successful 

 -*• one, though the attendance was smaller than it 

 would have been in happier circumstances, many mem- 

 bers being prevented from attending by more urgent 

 calls and duties. 



The shadows cast over the meeting by the war 

 were deepened for Section K by the news of the 

 premature death of Prof. D. T. Gwynne-Vaughan> 

 who had been for many years successively secretary 

 and recorder of the section. On Wednesday morning 

 the section adjourned as a mark of respect during 

 the hour of the funeral, A new departure which proved 

 of value scientifically was the setting apart of an 

 afternoon in which readers of papers demonstrated 

 their results, and others also gave demonstrations. 

 It afforded an opportunity for informal discussion 

 which was greatly appreciated. No sectional dinner 

 or excursions were arranged. 



The presidential address has already been given in 

 an abridged form in these pages. It embodied a plea 

 for the revival of the causal point of view in morpho- 

 logy, so long neglected in favour of the phyletic aim. 

 Using the alternating generations of the fern, the seed 

 and its embryo, and other examples, the president 

 illustrated the application of distinctively morphological 

 conceptions, such as specific substance, with " allo- 

 tropic" forms, and the correlation or mutual influence 

 of parts, to the study of form and structure, and 

 emphasised the significance for causal morphology of 

 " homologies of organisation," which have been the 

 bugbear of phyletic morphology. 



A feature of the meeting very appropriate in Man- 

 chester was a lecture by Mr. Lawrence Balls on the 

 application of science to the cotton industry. Survey- 

 ing the chief results of his experimental study of the 

 cotton plant in Egypt, he showed how, by suitable 

 sampling, trustworthy statistics could be obtained, 

 from which the growth, flowering, and fruiting of an 

 average plant under average conditions could be cal- 



