PHYSIOLOGY. 



688 



fore, tend to neulrali/e one another, the action 

 of one or the other being *een aeroniing to the 



Strength (if the do.-e. Until of these inlllleliees 

 arc temporary, and last but an hour or two. 

 The>e statement- n-fi-r to only small doses of 

 alcohol. It is possible that, had large quanti- 

 ties of alcohol been taken, the primary strength- 

 ening intluenee would have been followed \<\ 

 depressing after effects. 



In tlieir study of degeneration and regenera- 

 tion in peripheral nerve fibers after severance 

 of their connections with the nerve centers, 

 \V. 11. Howull and G. C. Hubcr divided the 

 rase- examined into two groups: Primary su- 

 tures, in which the surgical operation was per- 

 lormed immediately after the injury; and sec- 

 ondary sutures, in which the divided ends of 

 the nerve were dissected out and freshened after 

 the wound had begun to heal. In the latter 

 group the time interval between the suture and 

 the injury varied from a few days to years. 

 Synopses, in tabular form, are given in the au- 

 thor's paper, showing the number of failures 

 and successes for the different nerves operated 

 upon, the average time required in the success- 

 ful cases for the return of function to motor 

 and sensory fibers respectively, and other 

 points; and critical discussions of the cases are 

 attempted. The general conclusions of the au- 

 thors regarding the cases of primary suture 

 are that the prognosis is very favorable. In 

 all probability function will be restored com- 

 pletely or partially; that the prognosis is more 

 favorable the younger the patient; that some 

 form of animal suture is to be preferred, and 

 the majority of surgeons employ the "direct 

 method of nerve suturing; and that the clin- 

 ical as well as the physiological evidence is 

 against the possibility of " immediate union." 

 Of 80 recorded cases of secondary suture, 38 

 per cent, were successful, 50 per cent, were im- 

 proved, and 12 per cent, might be regarded as 

 failures. From a clinical point of view, then, 

 it might be said that the prognosis in the opera- 

 tions for secondary suture is good. Improve- 

 ment is almost certain, and in a large propor- 

 tion of the cases complete success may be ex- 

 pected. 



In the course of some researches respecting 

 the functions of the cerebral heat centers, I)r. 

 J. G. Adami made experiments to determine 

 whether substances inducing typical fever in 

 the intact animal lead to any rise of temperature 

 when injected into the animal deprived of its 

 hemispheres. Employing for this purpose the 

 hen, he found that for the first few days after 

 the removal of the cerebrum, when evidently 

 the shock caused to the system was still persist- 

 ing, the temperature regulating mechanism was 

 thoroughly disorganized. The bodily tempera- 

 ture of the fowl responded to changes of tem- 

 perature to which the normal hen is not or is 

 very little sensitive. The author, however, ob- 

 tained clear indications that the substances he 

 experimented with warmed egg and sterilized 

 cultures of Vibrio Metachnikom when injected 

 under proper conditions into the hen deprived 

 of its hemispheres, lead to a marked rise of tem- 

 perature. Whether such rise is truly febrile or 

 not, and whether it can be produced in fowls 

 minus their hemispheres at a later period, when 



the system is in a more stable condition, are 

 mailers that have \et to or investigated. 



The experiment- of lli-rn-tein and Wedenski 

 showed several years ago that tetanic stimula- 

 tion of a motor nerve in frogs causes no fat igue. 

 Howditeh, by the help of curare, obtained the 

 same results wkh reference to the cat and the 

 dog, or to warm-blooded animals. Langen- 

 doriT has adduced the persistence of toothache 

 as illustrating the existence of the same immu- 

 nity to fatigue in other nerves; and experi- 

 ments by Szana point to the same conclusion 

 with respect to the inhibitory fibers of the vagus 

 in the rabbit. 



Special Senses. In a paper on the "Func- 

 tion of the Retina in the Pereception of Color," 

 Mr. W. F. Stanley, referring to Young's theory 

 of color sensation, said that Prof. Rutherford 

 had pointed out that there was no necessity for 

 assuming that different nerves conveyed dif- 

 ferent color sensations, for as a telephone wire 

 would transmit almost an infinite variety of 

 sound vibrations, so the nerves of the retina 

 were probably equally capable of conveying all 

 kinds of light vibrations. Prof. Rutherford had 

 further pointed out that the image of a star 

 could not possibly cover three nerve terminals 

 at once, and therefor could not be seen as white 

 if Young's theory were correct. The author 

 then described Helmholtz's experiments with a 

 small hole in a screen illuminated by spectrum 

 colors. For red illumination the greatest distance 

 at which the hole could be seen sharplv defined 

 was 8 feet, and for violet 1J foot. When the 

 hole was covered with purple glass, or with red 

 and violet glasses superposed, and a bright light 

 was placed behind, the eye, when accommodated 

 for red light, saw a red spot with a violet halo 

 round it, and when focused for violet light, a 

 violet spot with a circle of red. These experi- 

 ments snow, the author thinks, that the chro- 

 matie sense in distinct vision under critical con- 

 ditions, or where a single nerve or a small group 

 of nerves is concerned, depends on the colors 

 being brought to foci at different distances be- 

 yond the crystalline lens. He also infers that 

 the same focal position in the eye can not convey 

 simultaneously the compound impression of 

 widely separated colors. Helmholtz's observa- 

 tions are further examined in the paper, and a 

 series of zoetrope and color-disk experiments are 

 described which tend to show that the eye can 

 not follow rapid changes of color. Changes 

 from red to violet could be followed much more 

 quickly than those from violet to red. The red im- 

 pressions were, however, more permanent. The 

 observed effects were found to depend on the in- 

 tensity of the light, and also on the distance of 

 the eve from the colored surface. Summing up 

 his observations, the author infers that by sys- 

 tems of accommodation of the eye, the colors' of 

 the spectrum are brought to focus on special 

 parts or points of the rods or cones of the retina, 

 such focal points being equivalent, by equal 

 depths or distances from the crystalline lens, to 

 a focal plane formed across the whole series of 

 nerve terminals. That all the rays of light from 

 an object, or part of an object of very small size 

 and of any spectrum color, will converge to a 

 point upon a nerve terminal, and that this ter- 

 minal will be most excited by the light. In the 



