BACTERIA AS PLANTS. 



b 



13. So - called arthrogenous 

 spores : a, Forming as segments 

 of rods ; b, As segments of a chain 

 of cocci. 



conditions. The same may happen among the 

 spherical forms, which only in rare instances form 

 endogenous spores. 

 Among the spheres 

 which .form a chain 

 of streptococci some 

 may occasionally be 

 slightly different 

 from the rest. They 

 are a little larger, 

 and have been 

 thought to have an 

 increased resisting 

 power like that of 

 true spores (Fig. 13 FIG. 

 b}. It isquite doubt- 

 ful, however, wheth- 

 er it is proper to re- 

 gard these bodies as spores. There is no good 

 evidence that they have any special resisting 

 power to heat like endogenous spores, and bac- 

 teriologists in general are inclined to regard them 

 simply as resting cells. The term arthrospores 

 has been given to them to indicate that they are 

 formed as joints or segments, and this term may 

 be a convenient one to retain although the bodies 

 in question are not true spores. 



Still a different method of spore formation 

 occurs in a few peculiar bacteria. In this case 

 ([Fig. 14) the protoplasm in the large thread breaks 

 into many minute spherical bodies, which finally 

 find exit. The spores thus formed may not be all 

 alike, differences in size being noticed. This 

 method of spore formation occurs only in a few 

 special forms of bacteria. 



The matter of spore formation serves as one 



