88 HISTORY AND CAUSE OF THE COCONUT BUD-ROT. 



GROWTH ON ENDO'S FUCHSIN AGAR. 



Endo's method has been particularly discussed by Herford ^ and 

 Kuata.2 B}' the latter it has been stated that one difficulty with the 

 method is the instabiUty of the medium, due to the looseness of the 

 combination of fuchsin with the sodium sulphite and the inconstancy 

 of the color reaction. Notwithstanding this objection, the writer 

 believes that the variation of the medium wall be the same for Bacillus 

 coll as for the coconut organism, so that the behavior of the organisms 

 on this medium can be compared regardless of any such difficulty. 



The method of making Endo's fuchsin agar as given by Ruata, is 

 as follows: 



Half a kilogram of powdered meat, 1 liter of water, 10 grams of peptone, 5 grams of 

 sodium chlorid, and 30 grams of agar are boiled together; the mixture filtered and 

 neutralized. Then 10 c. c. of a 10 per cent solution of sodium carbonate are added 

 in order to render the fluid alkaline. Finally, 10 grams of lactose and 5 c. c. of an 

 alcoholic solution of fuchsin are added. The medium assumes a deep-red color 

 which disappears on the addition of 25 c. c. of a 10 per cent solution of sodium sulphite. 

 The medium is then pom-ed into tubes, each containing 15 c. c, and is Bterilized 

 by steam. In order to obtain good results all the constituents of this formula must 

 be obtained pure, the solution of sodium sulphite must be kept well stoppered, and 

 the solution of fuchsin must be filtered before using and must be kept in a dark place. 

 When using this medium the agar, melted and cooled to 40° C, after inoculation is 

 poured into sterilized petri dishes where it is allowed to solidify. These dishes are 

 kept at 37° C, and after 15 hours colonies of the colon bacillus may be seen. After 

 24 hoiu^ these colonies become completely red and assume the greenish iridescence 

 characteristic of fuchsin. In contrast to this reaction on the part of the colon bacillus, 

 the typhoid bacillus remains colorless. 



Ruata states that in his experiments both the bacillus of typhoid 

 fever and Bacillus coli either turn the medium red or do not color it, 

 according to the variety of the germ and the particular source in 

 each case, as well as according to the nutrient medium in which they 

 have been cultivated, the age of the cultures, the quantity of the 

 material used for infection, etc. 



1 Herford, Max. Das Wachstum der zwischen Bacterium coli und Bacillus typhi stehenden Spaltpilze 

 auf dem Endoschen Fuchsinagar. Arbeiten aus dem Kaiserlichen Gesundheitsamte, vol. 24, 1906, pp. 62-67. 



s Ruata, Guido. II Metodo di Endo per la Diflerenziczione del Bacillo di Eberth del Bacillo del Colon. 

 Rcforma Medica, vol. 20, Apr. 27, 1904, pp. 449-453. Reviewed in the New York and the Philadelphia 

 Medical Journal, July 16, 1904, p. 126. 



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