18 



PHYSIOLOGY. 



Muscular System. In all forms of consider- 

 able muscular exertion respiration through the 

 open mouth is observed in healthy men. 11 

 breathing is of a "panting" nature, especia 

 when the man feels hot. The work of Gepperl 

 and Zuntz shows that in animals muscula 

 tivitv is accompanied by an increase in the oxy- 

 gen and a decrease in the carbon dioxide of 1 

 blood. The hyper-pnoea of muscular exercise is, 

 they consider, due to the effect of the same prod- 

 uct of muscular energy acting on the nervous 

 system. There appear, according to M. 8. I em 

 brey to be two other causes, one cardiac, the 

 other the increased heat of the body, of which 

 the latter is considered in the author's prelimi- 

 nary paper. The values obtained in the mouth in 

 Mr Pembrey's experiments and recorded m his 

 communication are too high for the temperature . 

 of that part of the body immediately after ex- 

 ercise, for the thermometer was retained for at 

 least ten minutes in the closed mouth. The ob- 

 servation was made in a warm room, and during 

 the time of making it the temperature of the 

 body was becoming more and more equal in its 

 various internal parts. In the experiments res- 

 piration only took place through the mouth when 

 there was actual and imperative need so to 

 breathe. The author suggests that buccal res- 

 piration in man may play a part in the regulation 

 of temperature during exercise. It increases the 

 loss of heat. The temperature observed in the 

 mouth in such cases is not a measure of the in- 

 ternal heat of the body. 



Experimental researches in biothermogene- 

 sis pursued by M. Raphael Dubois through sev- 

 eral years upon marmots have led him to the con- 

 viction that the heat produced by organisms, 

 particularly in the muscular system, should not be 

 regarded as simply a waste of physiological la- 

 bor, for elimination with the excreta, but a con- 

 dition of improvement useful and even necessary 

 to the performance of the physiological func- 

 tions. In order to a more complete demonstra- 

 tion of these facts he has undertaken to compare 

 in the same individual marmot the action of a 

 muscle normally and physiologically cooled with 

 that of the same muscle normally and physio- 

 logically warmed. Conclusions are drawn from 

 these experiments that the time lost from a mus- 

 cular contraction is one third shorter in a warm 

 than in a cold animal; that the duration of the 

 period of increasing activity and of decreasing 

 activity as well are one half shorter in the warm 

 marmot; that tetanization is obtained with a 

 number of excitations three times less in the 

 warm marmot; that the force of work is greatly 

 augmented in the warm marmot, which can not 

 only lift heavier weights, but can raise them to 

 a greater height and in a shorter time. The 

 ratio of the weights raised is ten times higher 

 in the warm animal; the muscle of the cold ani- 

 mal disengages less heat for the same excitation 

 and a smaller weight raised; muscular fatigue 

 is manifested much more quickly in the muscle of 

 the warm marmot than in that of the cold one. 

 The same effect is produced with the isolated 

 cardiac muscle of the animal. 



Nervous System. Prof.G.Golgi finds evidence 

 from the action of certain reagents of the pres- 

 ence of a special investing membrane in various 

 nerve cells, and also of a peculiar reticular struc- 

 ture in the interior of nerve cells. The cell cov- 

 ering disclosed by his experiments is sometimes 

 continuous and homogeneous and sometimes ap- 

 pears in the form of delicate scales deposited side 

 by side. More frequently, however, it presents 

 the appearnace of a fine and delicate network, 



with uniformly round and regular meshes, which 

 completely invests the cell body and is prolonged 

 upon the protoplasmic processes of the cell as 

 far as to the second and even the third division,. 

 but on these it becomes a more continuous and 

 homogeneous layer. The scalelike and striated 

 characters of the investment are particularly ob- 

 servable in the cells of Purkinje in the cerebel- 

 lum. The second structure mentioned is a deli- 

 cate network which the author shows to e\i-t 

 in the interior of the cell a reticular structure 

 that is so distinctive as to enable it to be easily 

 recognized even when seen only in a small seg- 

 ment of a cell. It consists of ilattened fibers ren- 

 dered brown by the action of the reagents u-rd 

 in the experiments, which unite in nodal points. 

 These nodes appear to be small disks of cir- 

 cular form, with transparent center. The fila- 

 ments near the periphery seem to be upon the 

 same plane, but nearer the center they dip in all 

 directions into the cell substance; peripherally 

 they terminate in pyriform swellings from whirh 

 again very fine filaments proceed toward the 

 periphery. Prof. Golgi regards the presence of 

 the external continuous or reticulated investment 

 of the nerve cell as opposed to the view that nerve 

 impulses are propagated by continuity; for it 

 would act as an insulator. 



Twenty recorded cases of transplantation of 

 nerves are referred to by Dr. R. Peterson in an 

 article in the American Journal of the Medical 

 Sciences. The median nerve was operated upon 

 in 7 cases, the ulnar in 3, the median and ulnar 

 nerves in 2, the muscular-spiral nerve in 7. and 

 the sciatic in 1. Eight of the operation- \\< it- 

 primary and 12 were secondary. The time from 

 the injury to the operation varied from forty- 

 eight hours to one and a quarter year. Kiglit 

 out of the 12 cases of secondary operation >luucd 

 improvement in sensibility or motion, while only 

 4 out of the 8 cases of primary operation im- 

 proved. The interval between the ends of tin- 

 divided nerves varied from 3 to 10 centimetre-. 

 but distance did not seem to affect the result. In 

 some cases the transplanted segments were from 

 the sciatic nerves of dogs, in 3 from rabbits, in 1 

 from a kitten, in 1 from the spinal cord of a rab- 

 bit, and in 5 from recently amputated limbs. In 

 9 cases catgut was used to unite the implanted 

 segments to the divided ends, in 3 silk, and in 1 

 kangaroo tendon. No case recovered entirely. 

 The nearest approach to complete recovery took 

 place in the case longest under observation, in 

 which at the end of six years sensibility had en- 

 tirely reappeared, and the only weak muscle vrai 

 the abductor pollicis. In 3 cases recovery of 

 sensibility and motion was practically had. and 

 the hand was useful. Muscular power improved 

 in 4 cases. Sensibility completely returned in 

 4 cases, nearly completely in 3 cases, and \\;i- 

 improved in 4 cases. Improvement in either mo- 

 tion or sensibility took place in 12 cases, and 

 no improvement in either in 6 cases. The aver- 

 age time in which sensibility appeared after tin- 

 operation was about ten days. Motion returned 

 in about two and a half months. 



The pathological changes produced in the 

 brain by sunstroke have been regarded as involv- 

 ing an acute parenchymatous degeneration of the 

 neuroses resulting from the action of an an 

 nous poison which was supposed to be the l>;i-i-> 

 of the symptoms. The subject has been further 

 studied by Dr. James Ewing from the nn-rop-y of 

 a deceased patient, in which a microscopical ex- 

 amination showed the anterior cornu celt- of the 

 spinal cord to have undergone character! -tic 

 changes, appearing diffusely stained and pale- 



