154 Lectures on Bacteria. [ xm. 



to the spores of endosporous Bacilli, but no further description 

 is given of them. Judging from the figures of sporogenous speci- 

 mens, and assuming that this species does not differ altogether 

 in behaviour from other endosporous Bacteria (see page 15), 

 the rods must be segmented in the same way as those of Bacillus 

 Megaterium described above, for they are represented with 4-6 

 spores standing close in a row one above another, as in Fig. i, r. 

 If our assumption and the account given is correct, each of these 

 spores must lie in a short segment-cell. This agrees with the 

 fact, that in coloured preparations the rods are sometimes found 

 divided by narrow hyaline transverse septa into a series of seg- 

 ments not longer than broad, such as Zopf figures in his third 

 edition. To call these segments Cocci is only playing with words. 

 If young vegetating rods are divided into long segments, this is 

 another point of agreement with Bacillus Megaterium. After 

 this description I abstain from giving a figure of this species ; a 

 drawing of what has been at present seen would represent a 

 simple or interrupted black stroke. In Fig. i, <$-_/" and r corre- 

 spond with our present knowledge of the form of the Bacillus of 

 tubercle, except that the length of the rods in the latter species 

 is on an average not greater than the breadth of those of Bacillus 

 Megaterium in the figure. 



The living rods, according to Koch, are not motile. When 

 grown on stiffened blood-serum they do not liquefy it, but 

 remain on the surface, and there even when developed in com- 

 parative abundance they form thin dry scales of small extension, 

 which are shown under the microscope to consist of sinuously 

 curved swarms and bundles of single rods. 



The Bacillus of tubercle grows slowly as compared with most 

 other Bacteria, and in this respect resembles the Bacterium of 

 kefir. In cultures on serum 10-15 days elapse before growth 

 can be detected by the unaided eye. The result of an inocula- 

 tion is not apparent in less than 2-8 weeks. 



The attempts to cultivate this species outside the living animal 

 on any other nutrient substrata than those above-mentioned 



