i S98] 11 UDIMENTAR Y NEB VO US S J r STJEM 387 



ments need to be performed in a dark room, or at night, by illuminat- 

 ing the liquid with the somewhat oblique rays of a candle so as to 

 obtain a marked shadow. Fill a floating dish with water and pour 

 on its surface a small quantity of petroleum. (Fig. 21.) This forms 

 large drops, on the edges of which appear certain pseudopodia with 

 terminal spheres : these advance inwards originating therein several 

 curious phenomena which are of no consequence at present. 



The drops of petroleum playing the part of the neuroplasma or 

 that of the nervous elements in evolution, project a distinct shadow 

 on the white ground of the dish. Water is the actor intrusted with 

 the all-important part of the neuroglia. 



Some other liquids may likewise serve the purpose, since there 

 is nothing indispensable, except the question of their densities and 

 the indissolubility of the one in the other. 



In fig. 21 there are five large masses of neuroplasm scarcely 

 differing from each other (young foetus). But when any waves are 

 produced in a single direction (acoustic impressions for instance) A 

 and B are divided (fig. 22) and six different elements result from 

 this mechanical division. Then, whenever the vibration continues 

 with increasing intensity, one of the drops lengthens, adhering by 

 one of its sides to the neuroglia or water, and finally constituting 

 a kind of myelocyte, undergoes tension in several directions and 

 sends the element c forth. We now have eight drops instead of 

 the five primordial ones and a very small one, a little like the 

 nervous embryonic cells (fig. 23). Still the experimenter goes on 

 his task of differentiation and provokes many waves in two directions, 

 obtaining thirty-seven more or less deformed drops (fig. 24). To 

 close the experiment a new undulatory motion is provoked with a 

 thick pin in a single direction and some currents of bipolar, multi- 

 polar, apolar, and articulated cells are formed, some resembling 

 neuromata, while others are elliptical and have nuclei in them. 

 (Fig. 24.) Though these figures are transitory I believe that per- 

 manent ones could be obtained by employing a melted grease which 

 would preserve the shapes acquired by vibration as it cooled. The 

 vibration can be provoked either in the water or in the floating 

 drops of petroleum themselves. 



Conclusions. — The origin of individuals and the construction of 

 the organism by internal conditions is an exceedingly probable 

 principle ; even the origin and functions of the nervous system may 

 generally be explained by vibrations, by waves running through 

 certain conductors of neuroplasma and modifying it mechanically 

 with regard to its shape, division, and connections. Every cause 

 influencing general nutrition will modify the physical and chemical 

 properties of the neuroplasma and of the neuroglia in whose bosom 

 it slowly performs its boundless evolution. 



