INFANTILE PARALYSIS 543 



the line drawn between the posterior corners of the eyes, the 

 diameter of the trephine being about ^ inch. A little of the 

 emulsion is drawn up in a small syringe, having a fine needle, and 

 two or three drops are injected beneath the dura mater. The 

 operation is carried out with antiseptic precautions, the wound 

 closed, and a little wool and collodion dressing applied. 



If the material injected be from a rabid animal, the first symptoms 

 will be noticed in from ten to fourteen days. The inoculated animal 

 loses control over its hind legs and throws them about peculiarly 

 when running. This increases, and in another day or so the 

 animal is apt to fall when running, and in another day or two the 

 hinder extremities become paralytic, and the animal is unable to 

 move, and dies shortly. The onset of symptoms is hardly ever 

 delayed beyond twenty-one days. 



Van Gehuchteri's method. The ganglion is placed in absolute 

 alcohol for twelve hours, the alcohol being changed once ; it is then 

 embedded, and sections are cut. These are stained for five minutes 

 in Nissl's methylene-blue and mounted. Or the material may be 

 fixed in 10 per cent, formalin before staining. The capsular changes 

 are best shown by staining with haematoxylin and eosin. 



Babes' method. A piece of the medulla or cord is hardened in 

 alcohol and stained with anilin red, and sections are prepared. 



Infantile Paralysis 1 



Infantile paralysis or acute anterior poliomyelitis occurs 

 sporadically and also in epidemics. 



Various organisms have been described in this disease, 

 but recent researches, particularly by Levaditi, Land- 

 steiner, and Flexner, have proved that the virus is a 

 filter-passer. 



Injection of emulsions of the affected cord into the 

 brain, spinal cord, peritoneal cavity, and blood-stream 

 of monkeys reproduces the disease with the same clinical 

 and pathological features as in man. The disease can 

 be carried on from monkey to monkey by inoculation, 



1 See Levaditi, Journ. Roy. Inst. of Public Health, vol. xix, 1911, pp. 1 

 and 65 (Bibliog.) : Flexner and others, Journ. Amer. Med. Assoc., 

 1910-1911. 



