612.8 384 



II 



Artificial Formation of a Rudimentary Nervous 



System : 



(d) Inhibition. — CI. Bernard's theory of nervous interference, 

 can be corroborated by producing two excitations of an almost 

 equal intensity at the ends of a big thread of mercury and by 

 putting two halves of a tube of caoutchouc in the midst of the 

 thread's surface. This tube performs the part of a heart, because 

 its halves alternately approach and part at the passage of the 

 waves. (Fig- 8.) Rest is doubtless the issue of the wave inter- 

 ference. (Action of the internal branch of the spinal.) 



(e) Formation of the dilated parts of the nervous system 

 by means of wave interference. — The continual excitations 

 applied to both ends of the thread of mercury, originate the forma- 

 tion of a central dilatation. (Fig. 8'.) It, then, seems probable that the 

 ganglions, plexus and dilated parts of the embryonic system, whose 

 consistence appears to be even softer than that of adults, are owing to 

 the continuous shocks of the vibrating waves that cause the unequal 

 distribution of nutritive materials or the movement and concentra- 

 tion of the already constituted parts. Now, if the consistence of the 

 neuroplasma increases, one may be sure that the construction of the 

 definitive dilated parts has been finally attained. 



This is, in fact, an extremely important cause of differentiation 

 and consequently of progress. In higher animals the most con- 

 tinuous and intense sensations terminate in an excessive division of 

 the nervous elements confined to the neuroglia. I have dis- 

 covered that the consistence of the latter presents an exceptional 

 importance. For instance, if you wish to obtain a great number of 

 multipolar cells anastomosed almost in the same manner as those of 

 the gray substance, you have but to place on some lard any viscous 

 liquid (coloured albumen, saliva). 2 Even the action of a terminal 

 resistance on a big thread of mercury (augmentation of consistence, 

 inclination, etc.) suffices to obtain the claviform or cerebriform 

 shape. 



(/) On the action of moderating nerves. — These are 



1 Continued from p. 339. The figures referred to are on p. 334. 



2 Models of multipolar cells. Natural Science, August 1898. 



