476 THIRD PART. BACTERIA OR SCHIZOMYCETES. 



or Mycetozoa. This would not affect the relations between the Endosporous and 

 Arthrosporous Bacteria, or between the latter and the Nostocaceae; nor can there 

 be a doubt that the Nostocaceae which contain chlorophyll and phycochrome are 

 in any case further removed from the Flagellatae than the allied species of Beggiatoa 

 and other arthrosporous forms, and that they therefore occupy the other extremity 

 of the whole series, which has received the name of Schizophytes and is the more 

 remote from the supposed point of departure. 



With respect to the coordination of the Endosporous Bacteria and the. rest of 

 the Schizophytes, we can only repeat what has been already said, that the final 

 determination of the point must be deferred till we are in possession of more perfect 

 knowledge of single forms. 



CHAPTER XI. MODE OF LIFE OF THE BACTERIA. 



SECTION CXXXIV. Capacity of germination and power of resistance in 

 the spores. All spores of Bacteria in which the point has been investigated are 

 capable of germination from the moment that they are mature, provided that the con- 

 ditions are favourable. If prevented from germinating they show wonderful power 

 of resisting the external agencies which are usually pernicious or fatal to living 

 organisms, and individual spores show this power in different degrees in different 

 species. 



These points have not yet been sufficiently investigated in the Arthrosporous 

 Bacteria. Kurth 1 found that the spores ('cocci') of his Bacterium Zopfii are killed 

 in from 17-26 days, when dried in a moderately high temperature (37 C.) and 

 then kept in an air-dry state at the ordinary summer temperature, while the vegetating 

 rods of the same species died in 7 days when subjected to the same treatment. 

 In a heated fluid their death-point is about 56 C. Similar small powers of resistance 

 to desiccation and high temperatures would probably be found in most of the 

 forms, such as Beggiatoa and Crenothrix, which are adapted to vegetate in water. 



On the other hand the spores of many endosporous forms are instances of the 

 highest powers of resistance. Those of Bacillus subtilis retain their vitality for 

 years when kept in an air-dry condition, and those of B. Anthracis will remain 

 alive, according to Pasteur 2 , in absolute alcohol and after being exposed for 2 1 days 

 to the influence of pure oxygen compressed by a pressure of ten atmospheres. We 

 have no precise observations extending over larger periods of time, but Brefeld 

 found the power of germination unimpaired after the lapse of three years when the 

 spores were kept in an air-dry condition, after the lapse of one year when they had 

 lain in water ; and from these facts as well as on account of other characteristics to 

 be noticed presently, we may safely assume that their powers of resistance are at 

 least equal to those of the most resistent spores of Fungi (page 344). The spores of 



1 Bot. Ztg. 1883, 409. 



2 Charbon et septicemie (Comptes rendus, 85 (1877), P- 99)- 



