November 21, 1901] 



NATURE 



65 



of the negative variation of strychnine convulsion, and Griitzner's 

 of that accompanying the spinal reflexes of the frog had shown 

 the way to an electric examination of reHex action. His own ob- 

 servationsexemplifiedhovvstrictlythe electric propagation through 

 the reflex cell-chain conformed with the direction laid down by 

 the Bell law of root-conduction. The electrical discharge in the 

 reflex action he found to be an irregular one compounded of an 

 irregular series of individual discharges. 



Closely connected with such communications as these was 

 a large group that may be classed as neurological. Prof. 

 Langley (Cambridge) has begun an attempt to determine the 

 group reactions to drugs and blood conditions of the dift'erent 

 neurons which make up the nervous system. He demonstrated 

 the stimulating action of nicotin on the neurons of the 

 superior cervical ganglion in testimony of his view that that 

 drug alters the cell-bodies (perikarya) of that ganglion. 

 Since the suggestion of Carl Ruber (Ann Arbor, U.S.A.) it has 

 been customary to suppose that the incidence of action of nicotin 

 in the sympathetic ganglia lies at the terminal fibrils of the pre- 

 ganglion neurons. Langley finds that if the preganglionic fibres 

 are cut and allowed time for regeneration the local application 

 of nicotin to the ganglion still produces its normal stimulating 

 effect. Nicotin applied to a ganglion of the sympathetic chain 

 causes erection of hairs only in the region supplied by the ganglion : 

 if it stimulated the preganglionic nerve-endings axon-reflexes 

 would move the hairs in other regions. Nicotin probably does 

 not paralyse spinal ganglion cells ; it does not stop the passage of 

 impulses through the bipolar cells of the spinal ganglion of the 

 skate. The erection of the hairs of the cat which occurs after 

 asphyxia does not occur if the sympathetic pilomotor nerve- 

 cells have been separated from the spinal cord ; this blood 

 stimulus acts, therefore, on the intraspinal pilomotor cells. 

 Prof. Langley also spoke, in illustration of the same theme, of 

 the effects of suprarenal extract on a number of tissues and 

 organs where he had examined its action. His new results, 

 together with others previously ascertained, showed that 

 in all cases the extract produces an effect of the same kind as 

 that produced by stimulation of the sympathetic nerve, and not 

 like that produced by a cranial or sacral autonomic nerve. Not- 

 withstanding this the action of the extract appears to be directly 

 upon the tissue, not upon the sympathetic nerve-endings : thus 

 it produces pallor and secretion of the submaxillary gland, and 

 this after degeneration of the post-ganglionic fibres of the cervical 

 sympathetic. The inhibitory effect of the vagus upon the 

 cardiac sphincter of the stomach was demonstrated to the 

 meeting. 



Prof. Langendorff (Rostock) reported upon restoration of 

 function which had occurred 105 days after total extirpation 

 of the superior cervical ganglion of the cat. The signs of 

 paralysis in the eye had then nearly passed off ; they returned at 

 once on section of the sympathetic nerve in the neck. Electrical 

 excitation of the upper end of the cut nerve-trunk gave strong 

 dilatation of the pupil, and palpebral fissure and retraction of 

 membrana nittilans. Microscopical examination failed to reveal 

 any reappearance or regeneration of the ganglion, but the sym- 

 pathetic fibres must have found their way to their appropriate 

 end-slations. 



Dr. Bottazzi (Florence) reported observations on the in- 

 nervation of the viscera in certain Crustacea and in elasmo- 

 bianchs. His communication was illustrated by a number of 

 anatomical preparations and photograms showing the disposition 

 of the nerve-trunks and the structure of the ganglia. 



Dr. Marenghi (Pavia) demonstrated rabbits in which he had 

 performed — as in one case was proved to the meeting by autopsy 

 of an animal — intracranial section of the optic nerve, and still 

 found persistence of reaction of the pupil to light and shade. 

 The reaction was feeble and sluggish, but indubitable. 



Prof. Flechsig (Leipzic) gave a very complete demonstration 

 of preparations recording the history of the myelinisation of the 

 nerve-fibres of the human brain. He described at considerable 

 length, with the aid of projected slides, his views regarding the 

 functional arrangement of dift'erent areas of the cortex cerebri. 

 Cortical fields to the number of thirty-six, uniform in extent 

 and distribution in different individual brains, can be mapped out 

 by the myelogenelic method. These fields are divisible chrono- 

 logically into three groups: primary i-io, intermediate 11-31, 

 \ terminal 32-36. The primary fields included the seats of cortical 

 representation of all the senses. The myelinisation in each of the 

 fields begins fairly contemporaneously throughout it and does not 

 begin from a single point in it ; neither the size of the nerve- 



NO. 1673, VOL. 65] 



fibres nor the vascularity of the tissue conditions the myelinisa- 

 tion of the area. Each primary field possesses a couple of well- 

 defined conjugated tracts, one proceeding to it — cortico-petal 

 and the earlier to myelinate — the other proceeding from it— 

 corticofugal and the later to myelinate. The primary fields 

 possess each a corticofugal tract which proceeds to regions non- 

 cortical. The intermediate and terminal fields possess no such 

 " projection " tracts. Prof. Flechsig regards both the cingulum 

 and the fasciculus longitudinalis inferior as projection tracts from 

 two of his primary fields; he believes, as Prof. W. FL Thompson 

 has previously urged, that the latter tract connects the cortical 

 visual field with the corftis geniciilatiim laterale. The inter- 

 mediate fields, on the other hand, are rich in long association 

 fibres leading to connection with other regions of the cerebral 

 cortex. 



Drs. Z. Treves (Turin) and A. Aggazzotti (Turin) reported 

 the interesting results of an attempt to train the flight of a 

 pigeon whose cerebral hemispheres had been removed. The 

 bird, with another whose hemispheres were similarly removed 

 at the same time, was allowed at first to remain, as pigeons after 

 ablation of the hemispheres do, perched almost motionless 

 on their wooden perch. The top of the perch offered an area 

 some five centimetres by four. After some days it was removed 

 from the top of the perch and placed about five centimetres from 

 it, and was pushed towards it and in various ways incited to fly 

 up to it. In fifteen days it began to take a short but fairly 

 perfect flight to the perch-top. The distance was increased 

 gradually by five centimetre increments. In five months' time 

 by daily training the distance of flight had been extended to 

 about eight metres. Sometimes the course of the flight was 

 straight, often it was not so. Resting places were introduced 

 sometimes not in a direct line to the perch in the cage. In six 

 months' time progress had been made so far that the bird when 

 thrown into air in a direction away from the cage orientated 

 itself promptly and turned its flight in that direction. In nine 

 months' time the bird flew regularly and well to the perch in 

 the cage from any quarter of the room and when started in any 

 direction. It, however, never once flew down from, or indeed 

 left, its perch of its own accord, nor did it ever feed itself. From 

 Turin it was taken to Modena for a fortnight and made to 

 learn other exercises. On being brought back to Turin and 

 liberated in its room it at once flew back to its cage and 

 mounted its platform. It seemed to possess memory. The 

 companion bird, to whom no training was given, at the end 

 of nine months did not, when placed close to its perch and 

 incited to fly to it, respond by flight, nor could it of itself, when 

 placed just outside the cage, fly into the cage. Both birds 

 retained throughout the strange huddled appearance and attitude 

 characteristic of the pigeon after removal of the cerebral hemi- 

 spheres. 



Dr. A. S. Griinbaum and Prof. Sherrington (Liverpool) 

 demonstrated a number of brains and cord-sections of anthropoid 

 apes on which they had been investigating points in the physio- 

 logy of the " motor area." Both excitation, by faradic elec- 

 tricity, and ablation had been employed. In view of the near 

 approach of these brains to the configuration of the human 

 it became obvious that the determination of the topography of 

 the excitable and other areas must be in them of considerable 

 practical importance to the study of human cerebral disease. 

 They had at outset of their work been surprised to meet with 

 results at variance with the topography generally .accepted as 

 probably obtaining in man. It had to be remembered, however, 

 that the generally accepted topography was based chiefly on 

 results obtained in the lower, not in the higher, apes, and that of 

 the anthropoid apes only a single species, and that by a single 

 specimen only, had previously been laid under experimental 

 contribution. Their own experiments, embracing observations 

 upon a series of chimpanzees as well as on the orang and the 

 gorilla, were completely unanimous in denying any extension of 

 the " motor region " to the surface behind the Rolandic fissure. 

 Nor had they found the fissures in the motor region inexcit- 

 able, as had been asserted for the cortex of the orang, or 

 that the motor region of the anthropoid required faradic currents 

 much stronger than those required for the lower monkeys, 

 A number of details were shown and dealt with in the 

 communication, account of which limits of space preclude our 

 here doing justice to. A chimpanzee taken to the Congress for 

 actual demonstration of the excitation effects became ill on the 

 journey and succumbed before experiment could be under- 

 taken. We may remark that the research showed more clearly 



