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PHYSIOLOGY. 



magnetizing force. The receding side would be 

 repelled more powerfully than the other, and so 

 the motion would be kept up. There are several 

 ways of reconciling this conclusion with received 

 ideas. Perhaps the action may be instantaneous. 

 Perhaps, according to Parker, actual diamagnet- 

 ism has no real existence. Lodge suggests that 

 the energy of the supposed perpetual motion 

 might be obtained at the expense of the magnetic 

 field because the spinning of the wheel may de- 

 magnetize the permanent magnet. The forces 

 concerned are so small that actual experiment 

 can hardly decide the matter. 



PHYSIOLOGY. In his presidential address 

 before the biological section of the British Asso- 

 ciation, Prof. J. S. Burdon Sanderson pointed 

 out that physiology had suffered in interest from 

 the separation which had been made of it, in the 

 splitting up of the sciences, from morphology. 

 While morphology, studying the order of the 

 plant and animal world, was attractive to the 

 beginner and satisfactory to the mature student, 

 physiology presented difficulties which are apt 

 to be discouraging to the beginner ; while to the 

 mature student it fails to present a system of 

 knowledge of which all the parts are interde- 

 pendent and can be referred to one fundamental 

 principle comparable to that of development or 

 evolution. Now that the best minds are directed 

 with more concentration than ever before to 

 those questions which relate to the elementary 

 endowments of living matter, the author could 

 predict that it was in that direction of element- 

 ary physiology that the advance of the next 

 twenty years would be made. The work of 

 investigating the special functions of organs, 

 which during the last two decades has yielded 

 such splendid results, is still proceeding, and 

 every year new ground is being broken and new 

 and fruitful lines of experimental inquiry are be- 

 ing opened up ; but the further the physiologist 

 advances in this work of analysis and differen- 

 tiation the more frequently does he find his at- 

 tention arrested by deeper questions relating to 

 the essential endowments of living matter, of 

 which even the most highly differentiated func- 

 tions of the animal or plant organism are the 

 outcome. In our science the order of progress 

 has hitherto been and will continue to be the re- 

 verse of the order of Nature. Nature begins 

 with the elementary and ends with the complex 

 (first the amoeba, then the man). Our mode of 

 investigation has to begin at the end. And this 

 not merely for the historical reason that the first 

 stimulus to physiological inquiry was man's rea- 

 sonable desire to know himself, but because differ- 

 entiation actually involves simplification. Phys- 

 iology, therefore, first studies man and the higher 

 animals, and proceeds to the higher plants, then 

 to invertebrates and cryptogams, ending where 

 development begins. From the beginning her 

 aim has been to correlate function with struct- 

 ure at first roughly, afterward, when her meth- 

 ods of observation became scientific, more and 

 more accurately the principle being that every 

 appreciable difference of structure corresponds 

 to a difference of function ; and conversely that 

 each endowment of a living organ must be ex- 

 plained, if explained at all, as springing from its 

 structure. It is not difficult to see where this 

 method must ultimately lead us. For inasmuch as 



function is more complicated than structure, the 

 result of proceeding, as physiology normally does, 

 from structure to function, must inevitably be 

 to bring us face to face with the functional dif- 

 ferences which have no structural difference to 

 explain them. Thus the investigation of special 

 organs, such as the eye, or a gland, like the liver, 

 leads up to plurality of function with unity of 

 structure, the unity being represented by a sim- 

 ple structural element be it retinal cone or cell 

 possessed of numerous endowments. When- 

 ever this point is reached, we take the problem 

 in reverse that is, use analysis of function as a 

 guide to the ultra - microscopical analysis of 

 structure. Some of the greatest advances in 

 physiological science have been made in this 

 direction, in which the recognition of function 

 has preceded the knowledge of structure. Dur- 

 ing the last ten or fifteen years histology has 

 carried its methods of research to such a degree 

 of perfection that further improvement seems 

 hardly possible. As compared with these subtle 

 refinements, the "minute anatomy" of thirty 

 years ago appears coarse, the skill for which we 

 once took credit but clumsiness. It is by differ- 

 ent methods of investigation that our better 

 equipped successors must gain insight of those 

 vital processes of which even the ultimate results 

 of microscopical analysis will ever be, as they 

 are now, only the outward and visible sign. 



Nervous System. The influence which leads 

 to the production of the convolutions on the 

 surface of the cerebrum and cerebellum is thus 

 explained by Dr. G. Jelgersma, of Meerenberg : 

 The gray cortex of the cerebrum, which in dif- 

 ferent forms of the same animal group preserves 

 a tolerably constant thickness, increases by sur- 

 face extension. Now, if we extend the surface 

 of a smooth-brained animal, say four times, we 

 must provide eight times as much white matter 

 to fill the interior of the gray capside, if we de- 

 sire to keep the surface even ; or, to put it in 

 different terms, if we lengthen out the radius of 

 the brain ten times, we acquire a surface exten- 

 sion one hundred times greater, and an internal 

 capacity one thousand times greater. The geo- 

 metrical law involved is that in the growth of a 

 body the surface increases with the second, but 

 the interior with the third power of the radius. 

 Such being the case, it is evident, seeing that 

 the proportion of internal white matter and ex- 

 ternal gray matter is in all cases uniform, that 

 in the evolution of a large animal from a small 

 one a disproportion between the gray capsule 

 and the white core of the cerebrum must result. 

 This is compensated for by the extended cortex 

 placing itself in folds or puckers, and thereby 

 reducing the capacity of the capsule to a degree 

 which brings it into correspondence with the 

 white contents. Consequently, " the formation 

 of the convolutions and furrows is simply the 

 result of the tendency on the part of the super- 

 ficial layer to increase by surface extension and 

 of a mutual space accommodation of the gray 

 substance and of the white conducting paths." 

 The same theory has been independently advanced 

 by Prof. George F. Fitzgerald, of Trinity College, 

 Dublin. 



The effect upon the bodily temperature of 

 lesions of the corpus striatum and optic thal- 

 amus has been studied by W. Hale White, M. D., 



