28o Journal of Comparative Neurology. 



tritive changes in the motor cells of the anterior horns, especial- 

 ly swelling and pallor of the nuclear bodies ; increase, breaking 

 up and finally dissolution of the Nissl bodies, increase of vol- 

 ume of the entire cell. These alterations are the more pro- 

 nounced the greater the concentration of the toxin. The in- 

 jection of the anti-toxin or the use of weak concentrations of 

 the poison still allows the cells to return to their normal state, 

 the swelling of the cell disappears and the nucleus takes on an- 

 gular shapes and returns to its normal volume. 



4. The greater the concentration of the poison, the more 

 rapid the evolution of these alterations, and also the more rapid 

 the restitution. Weak concentrations however produce very 

 slow alterations which may persist two or three weeks. 



5. The complete restitution of the Nissl bodies is ob- 

 tained more rapidly than that of the nuclear body. 



6. Not all the cells react exactly alike ; one often ob- 

 serves noticeable differences of intensity in neighboring cells. 

 Similar differences in the degree of morphological changes are 

 observed from one animal to the other (individual peculiarities). 



7. There is no accurate relation between the intensity of 

 the phenomena of intoxication and the degree of anotomical le- 

 sions of the cells. These can manifest a tendency to regenera- 

 tion at a time when the symptoms of intoxication are on the 

 increase and the reverse may be noted. The same dispropor- 

 tion between the anatomical and the physiological phenomena 

 has been ascertained by the writers in the experiments on 

 ' malonnitrile. ' This fact must be taken into consideration in 

 the appreciation of anatomo-pathological findings. 



8. The intravenous injection of the antitoxin of tetanus 

 exercises a manifest influence on the evolution of cellular alter- 

 ations by retarding them ; preventive injection hastens the on- 

 set of the phase of regeneration. 



9. The action of the antitoxin on the cells is beyond 

 doubt indirect. It consists in the neutralization of a quantity 

 of toxin bound by the cell. 



10. The morphological alterations of the cell are the ex- 



