HISTOLOGICAL CHANGES OF CENTRAL NERVOUS SYSTEM. 141 



PROTOCOLS. 



Guinea-pig No. 16. 25 mg. injected; dead in 8 minutes. Spinal cord and 

 brain placed immediately in 10 per cent formalin. Sections embedded in cel- 

 loidin. Stained with thionin (Nissl method). Examination of the medulla 

 and spinal cord showed no changes in the ganglion-cells. The vessels were 

 unaltered. 



Guinea-pig No. 21 . 20 mg. injected ; dead in 15 minutes. Brain and spinal 

 cord placed immediately in 10 per cent formalin. Sections embedded in cel- 

 loidin. Stained with thionin. Examination of sections of the medulla and 

 spinal cord taken at various levels showed no alteration in the cells or blood- 

 vessels. 



Guinea-pig No. 22. 20 mg. inj ected, dead in 30 minutes. Brain and spinal 

 cord placed immediately in 10 per cent formalin. Portions of medulla and 

 spinal cord were embedded in celloidin. Sections were cut at various levels 

 and stained Avith thionin. Microscopical examination showed no changes in 

 the cells or blood-vessels. 



Guinea-pig No. 18. 25 mg. injected, dead in 45 minutes. Brain and spinal 

 cord were placed immediately in 10 per cent formalin. Portions of the tissue 

 were embedded in celloidin, cut, and stained with thionin. Some of the vessels 

 in the medulla were dilated and congested. These vessels lie just beneath the 

 fourth ventricle. Some of the cells of the spinal cord (anterior horn) and 

 medulla (9th, 10th) took the stain a little more intensely. 



Rabbit No. 1. 15 c.c. of venom injected; dead in 1 hour 15 minutes. 

 Brain and spinal cord placed immediately in 10 per cent formalin. Portions of 

 tissue were embedded in paraffin. The spinal cord, medulla, and cerebellum 

 and pons were cut longitudinally. Sections were stained with thionin. Slight 

 changes were noted in the cells of the spinal cord (anterior horn cells), the 

 Purkinje cells in the cerebellum, and in a few cells in the nuclei of the cranial 

 nerves. Owing to the manner of cutting the sections the identification of the 

 cranial nuclei could not be assured, but it was evident that the toxin had no 

 selective action, for cells were affected in the various groups of ganglion-cells 

 throughout the medulla and pons. The changes to be noted were an early 

 disintegration of the Nissl bodies into a fine powder, starting around the nucleus 

 and proceeding to the periphery, a migration of some of the nuclei to the per- 

 iphery, and a slight swelling of the cells. These changes were to be noted in 

 only a few of the cells; the majority were normal. 



Rabbit a 3 . 25 mg. of venom injected; dead in 2 hours. Tissues hardened 

 and embedded as in rabbit No. 1. The changes in the cerebellum, pons, and 

 medulla were similar to those noted in rabbit No. 1, save that in the medulla 

 numerous small hemorrhages were found. 



Guinea-pig A v January 7, 1909, 1 capsule with 0.5 c.c; January 8, 1909, 

 5 p. m., dead. Died in 36 hours. Convulsions were noted, together with 

 weakness and paralysis. Tissues and sections prepared as above. Portions 

 were taken for study from several areas of the cerebrum, mid-brain, pons, 

 cerebellum, medulla, and spinal cord. Many sections were cut from these 

 areas. Some were stained with thionin and others with hemalum. 



Spinal cord : Sections from the cervical region showed swelling of the cells 

 in the anterior horn, a loss of staining reaction in the Nissl bodies, and dis- 

 placement of the nuclei. Hemorrhages were to be noted above and below the 

 central canal. 



Sections from the thoracic region showed similar changes in the cells and 

 marked congestion of the vessels throughout the white substance. 



Medulla: Sections through upper and lower levels. The changes in the 

 ganglion-cells were chromatolysis, swelling of the cells, and displacement of the 

 nuclei. The ganglion-cells of the cranial nuclei seemed equally affected. 



