206 PROTISTS AND DISEASE 



For this purpose Williams and Lowden recommend smears 

 made by placing small pieces cut by scissors from the Cornu 

 Ammonis, the Rolandic area, and the cerebellum. A 

 fragment is laid on a slide leaving room for a label, then a 

 coverslip is laid on the fragment and by even pressure made 

 to move to the opposite end of the slide. 



The smears are dried in air and stained either by Giemsa's 

 method after fixation in methyl alcohol, or by Mallory's 

 eosin-methylene blue stain after Zenker's fluid. Not only 

 Negri-bodies but also the swellings on the nerve-fibres, and 

 the collections of lymphoid cells are well shown by this 

 method, which the authors prefer to the section method. 

 Only in animals infected by fixed virus do sections give 

 better results than smears. The bodies were found on the 

 4th day in fixed virus cases, and on the 7th day in street 

 virus cases. 



The elements a, and 6, in Fig. 59 I drew from a section 

 kindly given me by Professor J. H. Ashworth, who had it 

 from the Pasteur Institute, Kasauli, India. It appears to 

 be stained with H. and E. We may note in the cell b that 

 the nuclear membrane is broken at the upper end and 

 granules appear to have been passing from nucleus to 

 cytoplasm ; below, again, a pyramidal process joins the 

 nucleolus to the nuclear membrane, as if in preparation for 

 a subsequent discharge of granules. 



Now it would be a reasonable suggestion that the Negri- 

 bodies resulted from a fusion of such granules. This would 



