vi] GENERAL CHARACTERS OF BACTERIA in 



of permanent seeds capable of retaining life under very 

 adverse conditions, and under favourable conditions capable 

 of germinating and of giving origin to a new brood of the 

 same species, can be shown to exist only in certain limited 

 species of bacilli, but not in micrococci or spirilla. These 

 real spores are endo-spores, they are formed within the 

 protoplasm of the bacillary elements under favourable con- 

 ditions, and they have certain definite morphological and 

 experimental characters of their own, at the same time re- 

 presenting as it were the last phase in the life-history of these 

 bacilH. Bacilli or bacteria not capable of this power of 

 producing spores, though they go on multiplying as long as 

 the conditions of nutriment, temperature, chemical by- 

 products, competition, &c., permit of it, ultimately degen- 

 erate, some sooner, some later. To propagate their species 

 they must as living bacilli find access to new soil before the 

 stage of degeneration is reached, whereas in the spore-bear- 

 ing bacteria their spores can remain dormant, but possessing 

 potential life for indefinite periods. 



The statement has been occasionally made that spores 

 are capable of dividing, and thus giving origin to two new 

 spores. The writer has not been able to detect anything of 

 this sort ; he has never seen any appearances that would 

 indicate such a division. True, in bacillus anthracis, in 

 bacillus filamentosus, and in some species of " potato 

 bacillus,'' spore formation may be going on so copiously that 

 at some places every element constituting the threads con- 

 tains a spore, some of the spores closely adjoining one 

 another, sometimes so closely that it looked as if they were 

 the two elements of a dumb-bell, and here a division of one 

 spore into two could be thought of ; but in these places the 

 elements of the threads were extremely short and the spore 

 occupied the main part of each element. It is also a fact 



