90 REVIEW — TKOPICAL MEDICINE, ETC. 



Hydrophobia 2. The " Negri bodies," as shown by the smears as well as by the sections, are specific to hydrophobia. 



— cuiili/iiied 3. Numerous " bodies " are found in fixed virus. 



4. " Bodies" are found before the Ijeginuing of visible symptoms, i.e. on the fourth day in fixed virus, on the 

 seventh day in street virus, and evidence is given that they may be found early enough to account for the 

 appearance of iafectivity in the host tissues. 



5. Forms similar in structure and staining (lualities to the others, but just within the limits of visible 

 structure at (1500 diam. magnification) have been seen. Such tiny forms, considering the evidence they give of 

 plasticity, might be able to pass the coarser Berkefeld filters. 



6. The "Negri bodies" are organisms belonging to the class Protozoa. The reasons for this conclusion are : 

 (a) They have a definite, characteristic morphology ; (i) this morphology is constantly cyclic, i.e. certain forms 

 always predominate in certain stages of the disease, and a definite series of forms indicating growth and multipli- 

 cation can be demonstrated; (c) the structure and staining qualities as shown, especially by the smear method of 

 examination, resemble that of certain known Protozoa, notably of those belonging to the sub-order Microsporidia. 



7. The proof that the "Negri bodies" .are living organisms is sufficient proof that they are the cause of 

 hydrophobia ; a single variety of living organisms found in such large numbers in every case of a disease, and 

 only in that disease, appearing at the time the host tissue becomes infective in regions that are infective, and 

 increasing in these infective areas with the course of the disease can be no other, according to our present views, 

 than the cause of that disease. 



A somewhat similar rapid method of diagnosis is that given by Frothingham.^* 



Cornwall' has a paper on recent advances of knowledge in connection with rabies, in 

 which he points out that "Negri bodies" can be demonstrated in brains which have been 

 ill-preserved and are even in a state of putridity. A microscopical diagnosis can now be 

 made in a day or so. If " Negri bodies " are found, rabies can be safely diagnosed. If not 

 fovmd, and the specimen is fit for inoculation into a rabbit, the biological test can still be 

 made, and in a few cases it succeeds where the " Negri bodies " have been missed by the 

 microscope. It is evident that early diagnosis is important in the case of patients unwilling 

 to go for treatment until the diagnosis is certain, while it is satisfactory for patients under 

 treatment to know that the latter is absolutely necessary. While "Negri bodies" are easily 

 found in the brains of animals dead from street virus, they are with difficulty found in fixed 

 virus-^ brains, and then only in very minute forms. All observers agree that rabic virus 

 filtered through a Berkefeld candle retains its virulence. The large " Negri bodies " cannot 

 pass this filter, so if, as Negri holds, the brain is thickly studded with minute forms or 

 spores, which are unstainable or ultra-microscopical, and, therefore, invisible, the filtrability 

 of the virus is an argument in favour of the parasitic nature of those bodies. 



Nitsch, while giving some very gratifying statistics as regards the Pasteur treatment 

 in his hands, indicates further improvements in the method by combining injections of 

 antirabic serum with injections of fixed virus, as Pasteur's method of immunisation can 

 only succeed in those cases which have a sufiiciently long incubation period to allow of 

 immunisation before the outbreak of the disease. 



Stefanescu^* has signalised the discovery of the " Negri bodies " in the salivary glands 

 of mad dogs, while Babes"* believes : (1) That certain very fine spherical, black or blue 

 bodies (Cajal-Gicmsa stain) found in degenerated nerve cells represent the parasites of 

 rabies in full activity; and (2) that the large "Negri bodies'' are encapsuled forms in process 

 of involution and transformation owing to the local reaction induced in the invaded cell. 



Lentz'' has recently described two new staining methods for the " Negri bodies," and 

 illustrates the results by two coloured drawings which give a very clear idea of the form of 

 the corpuscles. 



Negri,'* continuing his previous work, indicates a cycle of development for the bodies 

 bearing his name, which, though incomplete, is suggestive and strengthens the idea of their 

 being protozoa. There are two phases : (</) large chromatin masses breaking up into 



' Frothingham, L. (April, 1906). Journal of Medical Kcscarch, Vol. XIV. 



- Cornwall, J. W. (April, 1906), "Recent Advances of Knowledge in Connection with Babies." Indian Medical 

 Gazette, p. 121, Vol. XLII. 



" "Fixed virus" results from the serial passage of "street rabies" through rabbits. It is exalted in 

 virulence. — A. B. 



* Stefanescu, E. S. (May 18th, 1907). C. R. Soc. Biol, t. LXII. 



° Babes, V. B., Press Medical (October 20th, 1906), Zcil.j. Uyy., t. LVI., f. 3, May 24th, 1907. 



« Lentz, 0. (July 27th, 1907), " Ein Beitrag zur Fiirbung der Negrischen Korperchen." Ccnt.fui- liakt. I. Oria. 

 Bd. XLIV., p. 374. 



■" Negri, A. N. (May 5th, 1907). Rendie d. R. Ace. dci. Lincci, t. XVI. 



• Article not consulted in the original. 



