December 1898] RUDIMENTARY NERVOUS SYSTEM 385 
probably traversed by some wave-currents endowed with a 
celerity that gives them, in some measure, the means to oppose 
themselves to the currents coming from the ganglia of the sym- 
pathetic system as well as to those issuing from the viscera. Some 
disordered movements of the heart, intestines, etc., are naturally the 
result of the suppression of the action of the brain and medulla. 
This theory ought to be applied in cases of vascular inhibitions. 
(7) On the part performed by the medulla.— Les résultats 
contradictoires de plusieurs physiologistes au sujet de la fonction des 
cordons antérieurs et latéraux de la moelle, tenaient aux modes 
divers d’excitation mis en usage. Vulpian a constaté qu il faut une 
excitation trés énergique pour déterminer les contractions dans les 
muscles recevant leur innervation des parties situées au dessous du 
faisceau excité; que les attouchements, les piqtres, les grattages 
superficiels ne produisent aucun résultat, mais qu’on met en jeu 
Vexcitabilité de ces faisceaux en les pressant entre les mors-d’une 
pince.”* That is, until a powerful wave is produced. It is just the 
same with large masses of mercury, the vibrations of which cannot 
be brought about by rubbing them with a soft feather, and much 
less when the latter is protected by a cover. 
“Ta substance grise de la moelle ne conduit point les impressions 
sensitives par des voies anatomiquement préétablies, mais pour ainsi 
dire d’une maniére indifférente. Les sections transversales peuvent 
diviser la moelle epiniére dans une grande partie de leur épaisseur, 
et dans un sens quelconque, sans interrompre la transmission des 
impressions sensitives, & la condition qu'une petite partie de la 
substance grise (une sorte de pont) ait été respecteé par l’incision. 
L’animal conserve la possibilité de reconnaitre le point du corps 
irrité.. Vulpian parlait d'une sorte d’empreinte originelle des 
sensations. . . .”. The question is quite a simple one. The differ- 
ences are only in the intensity of the vibration occasioned by the 
variability of distance, degree of excitation, point on which it worked, 
protecting envelopes, etc., and as a matter of course the excitations 
are conveyed almost in the same manner and each of them reaches 
certain points of the sensorium, however small the bridge of the 
gray substance may be. 
Make a sort of a medulla with mercury and insert some con- 
ductors on its surface. (Fig. 10.) Some multipolar cells and con- 
ductory threads are then to be disposed in its upper part, as in 
Luy’s methods. A stronger excitation will then rise higher than a 
weaker one and the elements placed at different heights will be 
diversely effected. Each of these reacts on the motor threads, but 
only in case it be sufficiently excited. (Fig. 10.) In this manner 
the perception of simultaneous sensations and multiple reactions 
1 Kiiss and Duval, l.c., p. 67. 
