ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 499 



While the boiling is still going on, the neck is heated and melted off 

 (fig. 147). The tube is then laid in a horizontal position and rotated, so 

 as to spread out the gelatin into a regular layer, and care must be taken 

 to allow it to cool gradually. With practice, the whole transaction does 

 not take more than twenty to twenty-five minutes. 



The author remarks, that the addition of sugar renders meat-peptone 

 gelatin a more suitable medium for anaerobic bacteria. 



The foregoing method is only intended for the cultivation of such 

 bacteria as will thrive at temperatures under 24°-25'^ C, but the tubes may 

 be filled with agar or fluid media, and used for the examination of the 

 fermentation properties of anaerobic organisms. 



New Method for the Cultivation of the Tubercle Bacillus.*— MM. 

 Nocard and Eoux advise the use of sterilized serum, which is obtained from 

 the jugular vein of an animal (horse for choice). The blood is passed 

 aseptically into large sterilized bulbs, and then coagulated in fresh water 

 at 10°-12°. The serum is withdrawn with Pasteur's ball-pipettes. 



M. Nocard had previously determined that coagulated serum is rendered 

 more suitable for the cultivation of the bacillus by the addition of peptone, 

 soda, and sugar, and the authors now advise the addition of 6-8 per cent, 

 glycerin, which, they state, prevents the formation of the iridescent scum 

 on the surface of the serum from drying and oxidation, and even favours the 

 growth of the bacilli. 



Tubercle bacilli were found to grow well in agar-bouillon at 39° if 6 to 

 8 per cent, glycerin be added to this medium. 



The cultivations in media thus prepared grow more luxuriantly and 

 rapidly than by other methods, while they retain the staining and physio- 

 logical properties characteristic of tiibercle bacilli. 



Pure Cultivation of a Spirillum."!"— Dr. E. Esmarch has succeeded in 

 obtaining a pure cultivation of Spirillum from the dried-up remains of a 

 mouse which died of mouse septicaemia. A trace of the remains was inocu- 

 lated in gelatin, and from this a second tube prepared according to Koch's 

 fractional method. 



In the first tube more than 200 colonies of bacteria appeared within a 

 few days. These, which did not liquefy the medium, were of a yellowish- 

 grey colour, and in the course of another fortnight or so assumed a wine-red 

 hue. In the attenuation tube two colonies of bacilli soon showed themselves, 

 and after the lapse of fourteen days four new colonies appeared. These 

 were found to be identical with the red colonies in the first tube. Cover- 

 glass preparations showed that the colonies were a pure cultivation, and 

 consisted of short Spirilla, 



Cultivated in meat broth, the Spirilla were found to flourish best at a 

 temperature of about 37° C, copious development taking place within 

 twenty-four hours. At ordinary temperature eight to ten days were 

 required. 



In the original cultivation short Spirilla only, with two or three turns, 

 were noticed, but in the broth the number of turns became greater, amount- 

 ing to thirty, forty, and even fifty. The thickness of curve was always the 

 same, being about double that of the cholera Spirillum. The short ones 

 showed lively movements ; the larger were either motionless or moved in a 

 slow snake-like way. Cover-glass preparations were stained with the 

 ordinary watery anilin dyes for above five minutes. No flagella were 

 rendered evident. 



* Ann. Instit. Pasteur, i. (1S87) pp. 19-29. 



t CentralbJ. f. Bacteriol. u. Parasitenk., i. (1887) pp. 225-.S0. 



