3 6S 



NATURE 



[September 14, 191 1 



And now let us turn to the main function of this 

 developing system, which is to drive the blood in con- 

 tinual sequence past tissues that contribute to it and 

 tissues that abstract from it certain chemical materials, 

 and let us select the main incident, namely, the carriage 

 of oxygen from the lungs to other parts. That this is a 

 main incident is clearly shown by the fact that the red 

 corpuscles which form so important a feature in the 

 structure of blood are formed in a number directly equiva- 

 lent to this demand, that the blood should be capable of 

 transferring a certain quantity of oxygen. Thus if these 

 structures are lost by haemorrhage, or rendered less 

 efficient by the presence of carbon monoxide, or when 

 circumstances for the acquisition of oxygen are peculiarly 

 difficult, as on high altitudes, their formation is propor- 

 tionally accelerated. That negative pressure of oxygen 

 governs blood-production is a statement which will bear 

 some inspection. 



Now here we have a function which for its perfect 

 performance is dependent upon another machine, the 

 respiratory mechanism, which in its turn is governed by 

 a different but correlated factor, namely, the carbonic-acid 

 pressure in the blood. In this case we may say that the 

 positive pressure of carbonic acid dominates the quantity 

 of the respiratory activity. It is well known now that this 

 statement has been set on firm ground. 



It is interesting, then, to observe how these two 

 mechanisms are brought into exact correlation by the 

 simple fact that the lung surface, a portion of the respira- 

 tory mechanism, is formed accurately to a measure pre 

 vided by the volume of blood dispatched from the heart, 

 and therefore probably by that second growth of blood- 

 tissue which I have spoken of as due to pressure from 

 the heart. The surface of the lungs is some eighty square 

 metres. The heart at each stroke sends into the lungs 

 somewhere about too cubic centimetres of blood containing 

 red corpuscles within a total surface also of eighty square 

 metres. Here, then, we have a mechanical link connect- 

 ing these mechanisms that is obviously forged by an 

 incident of use. 



Within the central nervous system, where development 

 mainly affects the shape and distribution of structures 

 rather than their chemical quality, affecting thus what we 

 might call the geography of the system, interesting geo- 

 graphical facts attest to the same forged linkage of 

 mechanisms. Thus, for example, we have the so-called 

 " sympathetic system," offering at first view a curious 

 anomaly to the more usual, somewhat segmental, distri- 

 bution of nerve-fibres, since from the region of the cord 

 related to the trunk of the body nerves pass through this 

 system to control tissues placed in the head and in the 

 limbs. This anomalous geographical fact is, however, at 

 once explained when we regard the part played by this 

 sympathetic control in the several parts of the body as 

 merely subservient to the interests of locomotion. Under 

 its influence the eye is set for out-of-door, or, if I might 

 say it, for out-of-cave, vision. The heart is accelerated. 

 The glandular organs, with the exception of those useful 

 in times of much exertion and heat production, like the 

 sweat glands, are set at rest, or else the motor organs 

 of special importance in their sphere of influence are 

 quietened. Regarding the matter in this light, there is an 

 obvious convenience of geographical fact in the situation 

 of this instrument midway between those parts of the 

 central nervous system that are swept at this very time 

 by nervous impulses dominating the movements of the 

 limbs, just as there is some convenience in the chemical 

 linkage which has been discovered between the different 

 parts of this sympathetic system that further tends to 

 permit their unison of activity. 



On the other hand, when the muscles are at rest and 

 the condition of the body is of the indoor description, the 

 eye is set for close vision, and various glandular organs 

 are allowed to conduct their functions under the influence 

 of nervous mechanisms placed at some distance from the 

 disturbing centres of nervous activities that are used in 

 locomotion. 



Doubtless this useful distribution of parts within the 

 nervous system must find an explanation in the same 

 terms as must the dynamic anatomical relation to which 

 I have drawn attention as linking up the respiratorv and 



NO. 2185, VOL. 87] 



circulatory systems, namely, the fact that the heart sweeps 

 past the surface of the lungs at each stroke red corpuscles 

 that have the same extent of surface as the lungs. In 

 both cases it is true that the right adjustment of the 

 several parts of this machine has been arrived at as a 

 consequence of use, and that these mechanical linkages 

 are due to circumstances of a purely physical and chemical 

 nature. 



In conclusion, I might say that these instances have 

 been selected to illustrate my opinion that some of the 

 experiments of greatest interest to physiology are in process 

 of conduction within the normal body, and are to be 

 observed by records imprinted on its structures. In feel- 

 ing for the keys whereby each set of records may be 

 interpreted, it is necessary that someone should frankly 

 attempt to assign a definite meaning to every incident of 

 structure. That this attempt should be limited by precise 

 thinking goes without saying, and I may be allowed the 

 hope that my transgression outside the realms of precision 

 have not been beyond the tolerance of this section of the 

 British Association for the Advancement of Science. 



NOTES. 



A departmental committee (consisting of Mr. Angus 

 Sutherland, C.B., chairman, Mr. J. E. Sutherland, M.P., 

 Mr. H. M. Conacher, Dr. T. Wemyss Fulton,' and Mr. J. 

 Moffatt) has been appointed by the Secretary for Scotland 

 to inquire into and report upon the character and national 

 importance of the inshore and deep-sea fisheries of Norway 

 and other countries engaged in the North Sea fisheries, 

 and the efforts made for the development of the fishing 

 and fish-curing industry in all its branches, including 

 (1) the systems of fishery administration, including the 

 constitution and function of the local committees formed 

 for this purpose in Norway and of any similar organisa- 

 tions in the other countries ; (2) the facilities provided for 

 research and for educating and training those engaged in 

 these industries, by the establishment of technical schools, 

 museums, laboratories, classes, or other special facilities ; 

 (3) the nature of the various means of capture employed 

 and the methods (including any use of State credit) by 

 which fishermen obtain the necessary capital to maintain 

 the efficiency of their vessels and equipment ; and to report 

 in regard to each of the foregoing matters whether it would 

 be advisable for similar action to be taken, with or with- 

 out modifications, in the case of the Scottish fishing indus- 

 try, and, if so, what means should be adopted. 



Reuter messages from Catania state that frequent 

 earthquake shocks, some of which were fairly severe, have 

 been recorded at the Etna Observatory. The records in 

 the seismic apparatus are reported to be almost continuous 

 and very distinct. The volcano is throwing up dense 

 clouds of smoke, and a rain of cinders is falling as far 

 as Catania. There is also a broad stream of lava, which 

 is destroying the vineyards in its path. 



On Saturday, September 9, the aerial post was in- 

 augurated by Mr. Gustav Hamel, one of our most brilliant 

 flyers, who carried a sack of letters in a Bleriot monoplane 

 from Hendon to Windsor in thirteen minutes. Starting at 

 five minutes to five in the afternoon, he arrived at his 

 destination, nineteen miles distant, at 5.8, so that his speed, 

 the wind being behind him, was about 105 miles an hour. 

 The other aviators who should have started were prevented 

 by the thirty-mile wind, and no further deliveries took place 

 until Monday, when Messrs. Greswell and Driver carried 

 six mail-bags over in the early morning. M. Hubert, in 

 an effort to follow, had a bad fall, damaging his machine 

 and severely injuring himself. The affair has aroused 

 great interest, so much so that it is as well to sound a 

 word of warning and say that the aeroplane post is neither 



