255 
THE NATUEE AND SPECIFICITY OF 
NEGRI BODIES. 
By Captain HUGH W. ACTON, I.M.S., 
Assistant Director, 
AND Major W. F. HARVEY, I.M.S., 
Director, Pasteur Institute of India, Kasauli. 
With Plate XI aud 2 Text-figures. 
By many observers Negri bodies have been considered to be 
parasitic in nature (Negri, 1903 ; Babes, 1907). Williams and Bowden 
(1906) go furtlier and describe the life cycle of these bodies, regarding 
them as belonging to the Sporozoa, and give to them the name of 
Neuroryctes hydrophobiae. Calkins (1910), although he states that the 
parasitic nature of these bodies is not proven, still evidently inclines to 
that view. In his criticism of the work of Williams and Bowden he 
comes to differ from them as regards the classification of the supposed 
organisms. He thinks that their variable forms, the uninucleate 
condition, the occurrence of a state of distributed chromatin, and the 
budding phenomenon, are characteristic not of Sporozoa but of parasitic 
Rhizopods. His opinion is that the distributed chromatin masses in the 
Negri bodies are in all probability representative of the idiochromidia 
which are so characteristic of Rhizopods. 
On the other hand, many have doubted the parasitic nature of these 
bodies, as well as their specificity. Poor (1906) described in the 
tetanized guinea-pig, numerous very small inclusions resembling minute 
Negri bodies situated in the interior of the nucleus of the Ammon-horn 
cells. 
Bina Buzzani (1905) of Pavia examined the central nervous system 
of twelve cats suspected of rabies. In only two of them was she able to 
Parasitology iv 17 
