236 Experimental Researches on the ['fj:^ZXy"iX 



lY. — Experimental Researches on the Anatomical and Functional 

 Regeneration of the Spinal Cord. By MM. Masius and Van 

 Lair, Professors in the University of Liege. 

 Plate L. (lower half). 



VoiT has recently proved the reproduction of the cerebral tissue in 

 the pigeon, and the coincidence of this reproduction with almost 

 complete renewal of the cephalic functions. The facts which we have 

 collected tend to show that in the fi'og this regeneration of the spinal 

 cord also takes place, 



A certain number of authors have proved before us the cicatri- 

 zation of the spinal cord when simply divided, but no one has as 

 yet observed the reproduction of a segment of excised cord. "We 

 thus formulate the principal deductions which have resulted from 

 our experiments. 



The spjinal cord in the frog can recover instantaneously a loss 

 of substance which has tal'en place in its own tissues, and repair 

 its pirimitive anatomical and phijsiological properties. The grounds 

 upon which we base this assertion are of two kinds, anatomical and 

 physiological. 



I. — Anatomical Facts. 



The reproduction of the nervous elements takes place very 

 rapidly. This we have observed in a frog which had undergone 

 the excision of a medullary segment of 2 millimetres in size, a 

 month after the operation. The two ends are united by a cylin- 

 droid mass of yellowish translucent substance. A portion of this 

 gelatinous substance examined under the microscope mounted in 

 serum shows : — 



1. Very dehcate cellules, some of which appear spherical or 

 ovoid, and devoid of prolongations. Some of these are bipolar, 

 whilst others possess prolongations which can sometimes be traced 

 easily from one cellule to another. All the cellules are composed of 

 a finely granular protoplasmic mass, of a relatively large spherical 

 or ovoid refractive nucleus, surrounded by a membrane with very 

 clearly defined double contour. 



The nucleolus is brilliant, small, spherical, and always very 

 apparent, the prolongations are fine and pale, and appear to proceed 

 from the protoplasm (Fig. 3). 



EXPLANATION OF PLATE L. (lower half). 



Fig. 1. — Nerve-cells of forms met in the gelatinous substance, magnified 350 

 diameters. 



„ 2. — The Slime, undergoing pigmentary degeneration x 350 diameters. 



„ 3. — Cells of the gelatiniform substance with their anastomosing prolonga- 

 tions X 350 diameters. 



„ 4. — Fibres of Remak and varicose fibres found in the gelatinous substances. 



