Nc. C. 



DEPARTMENT OF AGRICULTURE. 



525 



tions the process is so widespread tliat all the ganglion cells are 

 destroyed. The intensity of these changes varies in different an- 

 imals; they are perhaps most pronounced in the dog, less marked 

 in man and still less in the rabbit. 



Much of the yalue of these lindings consists in their affording a 

 quick and sure means of making a diagnosis. It is possible to com- 

 plete the examination within six hours after the death of the 

 animal, and under ordinary circumstances a positive opinion can 

 be given in from twenty-four to thirty-six hours. It is important 

 that the animal should be allowed to die, and not be killed prema- 



t'ig. 3. Dissection of the upper neck of dog. showing the Plexiform G:inglioa of the Pneumcgas 

 trie nerve, in which the changes are usually sought for 1. Plexiform (ianglion. 2. Cervical 

 Ganglion. 3. External auditory meatus. 4. Atlas. 5. Inferior Ma.xilla. (Af ler Val ee-Di jgram 

 matlc). 



turely, as where the disease is not permitted to run its full course 

 ending in death, the changes may be absent or only slightly devel- 

 oped. 



The ganglion on the pneumogastric nerve is selected by prefer- 

 ence and should be removed as soon as possible after the death of 

 the animal. (Fig. 3.) It is put into absolute alcohol, or in 10 per 

 cent, formalin solution. If put into absolute alcohol it should be 

 removed to a fresh portion of alcohol at the end of six hours, in 

 which it remains for six hours, when it may be transferred for 

 one hour to a mixture of absolute alcohol and chloroform, and then 

 put for one hour in pure chloroform, then one hour in a mixture 



