PlIYSloLOOY; 



791 



the blood-vessels so that a force is constantly 

 in ..Pfijitii.ii to iiiaintiiiu the aiiioiint of blood 

 within the <-niiiijil vessels. The author acknowl- 

 cdu'e- that molecular actions of a subtile kiml 

 take place bet ween the blood and blood- \. 

 ami the nervous tissue-, and these are much le-s 

 active during sleep than during wakefulne--. 

 The lessened activity in the nutrition of the 

 nene protoplusin diminishes the activity of the 

 capillary circulation. The change in the bal- 

 ance of the circulation between the arteries and 

 capillaries on t he one hand and t he veins on t he 

 other is n-irarded by Dr. Cappie as the keystone 

 of the theory of the causation of sleep. The 

 altered balance of the circulation occasions a 

 change in the balance of active pressure, which 

 is not so much within the brain substance as on 

 the Mirface. It is less expansive and more com- 

 pressing, and with this compression conscions- 

 ne is suspended. In a new chapter "On Some 

 Points in Mental Physiology" Dr. Cappie con- 

 siders how fur the peculiarities of the encephalic 

 circulation may affect the functional activity of 

 the different parts of the brain. Starting from 

 the position that the brain is a composite organ, 

 and that different portions are put into a state 

 of functional activity in connection with the 

 discharge of their respective duties, the (|iiestion 

 of the balance of the circulation has again to Ixj 

 considered. For the part which is more im- 

 mediately concerned in the production of the 

 particular cerebral operation must become the 

 seat of vascular excitement, and the amount of 

 blood flowing through its vessels will be greater 

 than that transmitted through the vessels of 

 those other parts of the brain which are not for 

 the time so functionally active. Hence a cer- 

 tain tension of the area or center which is act- 

 ively working must arise, and the encephalic 

 circulation is focused in the direction of ac- 

 tivity. In applying his views on the encephalic 

 circulation to the explanation of the phenomena 

 of hypnotism, the author remarks that the first 

 incident in the hypnotic state is a steadily pro- 

 longed effort of volition in which the attention 

 is concentrated in a very restricted direction. 

 The immediate consequence is a fatigue of the 

 nerve centers concerned in keeping up the strain. 

 Their molecular motions become enfeebled, the 

 circulation through them is less active, and a 

 condition approaching that of sleep is produced. 

 If then, in the form of a suggestion from an- 

 other, some stimulus calls into activity a part of 

 the brain not fatigued in the effort of attention, 

 its vascular activity will be increased, and its 

 function will be intensified. 



Kxperiments by G. N. Stewart on the rela- 

 tions between temperature and endocardiac pr. - 

 ure and the action of the nerves of the batra- 

 chian heart show that both the vagus and the 

 sympathetic have their activity diminished as 

 tlie temperature is lowered, and increased jis the 

 temperature rises. Tin- sympathetic curve, how- 

 ever, falls more steeply with falling temperature 

 than does the vagus curve, so that the vagus is 

 generally still active with a temperature at 

 which the sympathetic has ceased to act. An 

 increase of encloeardiae pressure sufficient to 

 abolish the inhibitory action of the vagus leaves 

 the sympathetic still active, and the primary 

 augmentation, may be attributed to the sympa- 



thetic filer* in the mixed m-rvi-M. Hi-nt *Und- 

 slill of the heart, when then- i- n e.-n-iiu, 1 

 his acting, Mich a* a high cndm-nrdmc pn-Miire, 

 is always diaMolic. and i an ne\i-r IH ci<-< rl-d a 

 " heart (claim-. " 



Two Italian doctors have related, in the " Re- 

 vi.-la Speriincniale di l-'in-n/e." the n-idl of a 

 series of experiments undertaken to determine 

 the influence which the po-ti-rior inn- 

 have on the excitability of I lie anterior roots. In 

 the fir-t seric- of experiments the [M.stcrior root* 

 were treated with cocaine; in the -eci.nd. they 

 were divided; in the third, they were stimulated 

 electrically: and in the fourth series th* 

 was divided In-low the medulla. It was found 

 that when the |>osterior roots were rendered 

 functionless the excitability of the anterior root.- 

 was diminished; but when the p i-tehor roots 

 were M miniated, an over-excitability of the an- 

 terior roots was produced, which went on in a 

 short time to diminished or even abolished irrita- 

 bility, and the same results were found when the 

 cerebro-spinal svstem was intact, and when the 

 cord was divided below the medulla. 



Having shown that lesions either of the corpus 

 striatum or optic thalamusof the rabbit produce 

 a rise of bodily temperature, while lesions of the 

 surrounding white matter have no such effect, 

 W. Hale White, in subsequent experiments, at- 

 tempted to limit more precisely the positions in 

 this neighborhood causing a rise of temperature, 

 and also made experiments on other parts of the 

 brain. He concludes that, the normal rectal 

 temperature of a rabbit being between 101 

 and lOJJ F., neither an anaesthetic nor an opera- 

 tion on the brain affects the temperature much, 

 unless some special part of the brain is damaged : 

 that lesions of the corpus striatum, if not large 

 enough to give rise to shock and severe hirnior- 

 rhage, and lesions of the septum lucidum cause 

 a rise of temperature; that lesions of the optic 

 thalamus and of the cerebellum do not alter the 

 temperature, and lesions of the white matter 

 around the corpus striatum and optic thalamus 

 do not cause a rise; that lesions 01 the anterior 

 part of the upper surface of the cerebral vertex 

 either do not alter the tcni|>c rat lire, or the altera- 

 tion is very slight; that lesions of the posterior 

 part of the upper surface of the cerebral cortex 

 may cause irregular rises of temperature, which 

 are quickly produced and last only a short time 

 sometimes there are several rises and falls after 

 one operation; and that lesions of the cms 

 cerebri cause ;i considerable ri-e of temperature. 



It is well known that in some animals, when 

 they are under the influence of strong emotions. 

 the hair of particular regions of the body In- 

 comes erect (horripilation). Observations to de- 

 termine the origin in the central nervoi; 

 tern of these erections have been made in the 

 monkey by ('. S. Shcrringtoii. and in the cat by 

 .1. N. I-juiu'ley. The authors jointly publish the 

 conclusions that the hair of the monkey, cat. and 

 probably of all animals in which horripilation 

 occurs under the influence of -tronj: emotion, as 

 iejir or anger, may be erected by stimulation of 

 nerve fibers which issue from the spiiui 

 and piissthroutrh thcsympathctictici v. i:--\>tcm. 

 These hairs have no direct spinal supply. The 

 nei ve filers bv means of which tl erections oc- 

 cur are called pilo-motor nerve liU-rs. In the 



