On the Cultivation of Bacteria. By Edgar M. Crookshank. 31 



transmitted from cattle to cattle by inoculation, and a rabbit 

 infected by means of a piece of actinomycetic tumour from a human 

 subject, introduced into the peritoneal cavity. 



Until quite recently, Aciinoimjees has been classed as a hypho- 

 mycete, and the flask-shaped structures regarded as gonidia. From 

 recent cultivation experiments, Bostrom regards the latter as a 

 result of a degenerative stage in the life-history of the fungus. 

 Inoculations of nutrient gelatin in the form of plate-cultivations 

 and inoculations on blood serum and nutrient agar-agar, were made, 

 it is claimed, with success. The cultures developed in five to six 

 days, and best at a temperature of SS-ST'^ C. Nutrient gelatin 

 was not liquefied. The appearances of the cultivations were de- 

 scribed as quite characteristic ; a whitish granular appearance first 

 occurs, followed after a few days by little yellowish-red spots which 

 coalesce in the centre ; in time the periphery also becomes dotted 

 with little yellow-centred masses. The fungus thus cultivated has 

 been described on examination as corresponding with the form 

 found in man and animals, and further, at one stage to consist of 

 thread-forms, short rods, and cocci. From these observations, 

 Bostrom has come to the conclusion that Actinomyces should be 

 classed with the bacteria, forming one of the Cladothrix group, 

 and possibly closely allied to the Streptotlirix Forsteri of Cohn. 



In conclusion, I would draw attention to the preparations of 

 this fungus which are placed under the Microscopes on the table. 

 These preparations have been stained by methods somewhat recently 

 introduced. Very beautiful results can be obtained by either the 

 methods of Weigert or Plant. By the first-mentioned, sections are 

 immersed in solution of orseille for one hour. They are then 

 rinsed in alcohol, and placed in a solution of gentian-violet which 

 is employed as a contrast stain. (Plate IV. figs. 1 and 2.) 



In Plant's method, the sections are placed in G-ibbes' solution of 

 magenta warmed to 45° C. They are then rinsed in water, and 

 after-stained in concentrated solution of picric acid, for from five 

 to ten minutes. After this they are immersed in water five 

 minutes, laid in 50 per cent, alcohol fifteen minutes, passed through 

 absolute alcohol and clove oil, and preserved in Canada balsam. 

 (Plate V. figs. 1 and 2.)* 



* Plates III.-V. have been taken from Dr. Crookslaank's book on ' Practical 

 Bacteriology ' (see infra. Microscopy /3.), the original stones having been kindly 

 placed by him at our disposal for that purpose. — Ed. J.E.M.S. 



