270 DR. E. KLEIN. 



pork broth, used in my experiments on Anthrax bacillus. 

 With the egg I have not obtained any satisfactory results, but 

 with the gelatine and the mixture of gelatine and pork broth I 

 have obtained beautiful crops. The sowing was done with 

 the point of a capillary glass tube on to the free surface of the 

 nutritive material (contained in flasks or test-tubes, plugged with 

 sterilised cotton wool) ; and after an incubation of about four 

 days, the vessel being kept at ordinary temperature of the room, 

 there appeared the first signs of the growth having taken root, 

 in the shape of a minute pinkish droplet ; this gradually spread 

 in breadth and thickness. The very interesting fact observed 

 with this increase was this : the masses growing downward 

 into the nutritive material remained colourless, whereas those 

 spreading on the free surface were pink, both being composed 

 of exactly the same torula cells. 



The thicker the layer became, the deeper the pink tint. The 

 gelatine does not become liquified by the growth, and in this re- 

 spect it differs from a growth of micrococci, bacteria, or bacilli. 



Sowing the pink torula into the depth of fluid nutritive 

 material, such as pork broth, and keeping it at the bottom of 

 the fluid, it is noticed that no matter whether growing at ordi- 

 nary temperature of the room, or in the incubator at 30 — 35° C, 

 it remains colourless, and when of considerable amount, 

 appears like a whitish precipitate at the bottom of the fluid. 



Sowing this colourless torula on to a free surface, it again 

 gives origin to pink growth. But also in the same tube the 

 at first colourless torula, i. e. while growing at the bottom of 

 the fluid, may, when reaching the free surface, give origin to 

 the pink growth. 



Another interesting fact I have observed is this, that when a 

 copious growth of pink torula has made its appearance on the 

 surface of the solid nourishing material (gelatine), and this 

 nourishing material is made fluid, so that the pink growth 

 sinks to the bottom, and the material is again allowed to 

 solidify : it will be observed that the pink mass retains its 

 colour, that is to say, that the torula, once pink does not loose 

 its colour when removed from the free access of air. But the 



