534 



NATURE 



[October 19, 191 1 



the blood to the vessel wall, is a factor in preventing co 

 lation of blood in the vessels. Contact of amoeboid cor- 

 puscles with particles of carmine or Indian ink causes 

 phagocytosis if the surface tension between corpuscle con- 

 tents and particle is less than that between the plasma 

 and particle. When a corpuscle adheres to the wall of a 

 blood vessel it is driven outwards if the surface tension 

 between corpuscle and blood-vessel wall is less than that 

 between corpuscle and plasma, and hence diapedesis 

 occurs. The association of haemolytic and haemorrhagic 

 poisons may be due to a lowering of the surface tension 

 causing both processes. 



Mr. YV. W. Waller, an attempt to obtain photographic 

 records of the emigration of leucocytes. This was 

 illustrated by a number of photographs showing blood 

 vessels with white corpuscles escaping from them. Several 

 interesting points were mentioned, such as a tendency for 

 several corpuscles to escape at the same point, and appar- 

 entlv to form colonies after their escape. 



Dr. Hariette Chick and Dr. C. J. Martin, F.R.S., the 

 chemistry of heat coagulation of proteins. Coagulation 

 takes place in two stages, denaturation and agglutination. 

 Denaturation is due to the presence of water, depends on 

 the temperature, and is an exponential function of the 

 concentration. The temperature coefficient is remarkably 

 high. Egg albumin differs from haemoglobin owing to a 

 change in reaction during coagulation, but by using boric 

 acid to keep the hydrogen ion concentration constant the 

 eg^ albumin then behaves like haemoglobin. Increase of 

 acidity favours denaturation. Agglutination depends on the 

 concentration of hydrogen ions. Three factors, namely, 

 surface tension, electrical charge, and velocity of Brownian 

 movement seem to regulate the agglutination. 



Prof. Freundlich spoke on this communication, referring 

 to the importance of such investigations into the processes 

 of coagulation. 



Dr. YV. N. F. Woodland, recent views concerning the 

 physiology of gas production in connection with the 

 gas bladder of bony fishes. The structure of the rete 

 mirabile duplex is concerned with the secretion of oxygen. 

 1 he composition of the gas varies in different species. 

 The pressure of any particular gas may be greater than 

 thai in the blood stream, and hence there must be some 

 proi " of secretion. Fish which change their depth rapidly 

 secrete oxygen to compensate for the effects of pressure. 

 A weighted fish rises after some time, mainly due to in- 

 crease of oxygen in the swim bladder. It has been stated 

 that a toxin is formed which causes haemolysis of the red 

 blood corpuscles, but none was found as the result of 

 activity, nor, as previously stated, were gas bubbles found 

 in the secreting cells. The author urged physiologists to 

 undertake the study of the process of oxvgen secretion. 



Prof. J. S. Macdonald and Dr. J. E. Chapman, heat 

 production and body temperature during rest and work. 

 By means of the calorimeter at Sheffield the heat pro- 

 duction of a fasting man was determined at rest and then 

 during the performance of work. Heat output lags behind 

 heat production owing to a rise of body temperature, which 

 stores a certain amount of heat. The lighter the clothing 

 the more nearly the heat output keeps pace with the heat 

 production. Fatigue is not shown in the record of heat 

 output, but it is shown in the rate of cycling. 



Dr. H. E. Roaf, carbon dioxide output during decere- 

 brate rigidity. The carbon dioxide output was measured 

 during decerebrate rigidity, and then after abolishing the 

 rigidity. Abolishing the rigidity by curare or by cutting 

 the motor nerves did not lower the carbon dioxide output. 

 Hence decerebrate rigidity differs from ordinary muscular 

 contraction, as there is no increased production of carbon 

 dioxide during rigidity. 



Dr. F. W, Edridge-Green, the frequency of colour- 

 blindness in males. The percentage of colour-blind men 

 has been underestimated. The author finds at last 6 per 

 cent, are colour-hlind, and that 25 per cent, have 

 diminished colour-vision. 



Prof. G. J. Stokes, paramnesia. The author suggests 

 that the sami idea may reach the brain by two different 

 routes, one passing through a greater number of 

 synapses, and thus arriving' after the other. Hence in 

 in rases a feeling that the incident is not new, although 

 it could not possibly have happened before. 



NO. 2K)0. VOL. 8j~} 



Miss May Yates, the nutritive value of whole meal 

 and white bread. This was a correction of some state- 

 ments made in a recent Local Government Board report. 

 It was claimed that the report did not correctly compare 

 the nutritive value of white flour and flour without re- 

 moval of the germ and bran. 



Prof. A. D. Waller, F.R.S., read an interesting historical 

 paper reviewing the documentary evidence of the discover) 

 of the distinction between motor and sensory nerves. 



It was an unfortunate coincidence that the two foreign 

 guests who had accepted invitations as representatives ol 

 physiology should at the last moment have been preventea 

 from attending the meeting. Apart from this, the meet- 

 ing was an agreeable and interesting one for physiologists. 



AGRICULTURE AT THE BRITISH 

 ASSOCIATION. 



V 



HE outstanding event this year was the elevation of 

 agriculture to the position of a full section ; hence- 

 forward agriculture comes definitely within the purview 

 of the British Association, and permanently figures as 

 Section M. The increasing output of work by investigators 

 in this country fully justifies this step, while the great 

 interest always shown in agricultural matters by the 

 members of the association encourages the hope that the 

 new section will at least contribute its share to the 

 attractiveness of the meetings. 



The problems presented by soils, crops, and animals are 

 so complex that agricultural investigators are bound to 

 keep in close toucli with workers in pure science in order 

 that their methods and conclusions may be critically 

 examined. At the British Association meetings more than 

 anywhere else such critical discussions are possible, and in 

 permanently arranging for them the association is fulfilling 

 the first of its declared objects — " to give a stronger 

 impulse and a more systematic direction to scientific 

 inquiry." 



The president's address dealt broadly with the applica- 

 tion of genetics to the problems of agriculture and horti- 

 culture (see Nature, September 21), and several of the 

 papers dealt with special aspects of this subject. In an 

 interesting communication Mr. C. C. Hurst discussed the 

 genetics of horse-breeding. Chestnut coat colour is 

 recessive to bay and brown; consequently chestnut horses 

 always breed true when mated together, notwithstanding 

 their bay and brown ancestors. Bays and browns, how- 

 ever, are of two kinds, one throwing chestnuts, the other 

 not. Grey is dominant to bay, brown, and chestnut, but 

 since grey X grey matings are rare in England. English grey 

 thoroughbreds are nearly all heterozygous, throwing bavs. 

 browns, or chestnuts : a homozygous grey is, however, 

 known in Germany which throws nothing but greys. In 

 certain strains a partial coupling is observed between coat 

 colour and racing power, bay and brown descendants of 

 St. Simon being much better racers than the chestnuts. 

 There is apparently a partial tripling of brown coat colour, 

 high racing power, and female sex in St. Simon's own 

 offspring. 



Prof. Wilson described his studies of the inheritance of 

 milk yield in rattle, the earlier accounts of which have 

 attracted a good deal of attention. After eliminating 

 abnormalities due to time- of calving, period of lactation, 

 food, shelter, and age of the animal, it is found that full- 

 sized mature rows fall into three grades, giving, re- 

 speetivelv. 500 to 600, 650 to 850, and about 1000 gallons 

 of milk a year. The two extreme grades are approxi- 

 mately pure, while the middle grade is a hybrid. 



A different type of problem was dealt with by Mr. W. J. 

 Backhouse. A systematic inquiry was undertaken into 



the gi ii composition of our common plums with the 



view uf putting ilii' raising of new plums on a scientific 

 hasis. At the height of the flowering Deriod the flowers 

 of certain plums were carefully hand-pollinated with their 

 own pollen. Some varieties Droved remarkably self-fertile, 

 the flowers seiiino very well to fruit. Other varieties, 

 however, proved splf-sterile, ami set absolutely nothing. 

 It is understood thai tie-- interesting observations are 

 being followed up. 



A useful dav was sp.-nt in discussing the bacterial 



