THE STRUCTURE OF BACTERIA. 



2 9 



appear probable that some organisms that are 

 generally supposed to be bacteria, such as the 

 so-called tubercle bacillus, exhibit a type of 

 spore-formation which is homologous with the 

 chlamydospore formation of true moulds, such 

 as Mucor (Fig. 20). 



In addition to the true bacteria, or to those 

 organisms that up to this time have gone 

 under that head, which propagate by arthro- 

 spores in the narrower sense, or by gonidia 

 like some kinds of fission-algae, or by chlarny- 

 dospores after the manner of some kinds of 

 moulds, there are some bacteria which re- 

 produce in another and characteristic fashion, 

 namely by means of endogenous spores or 

 endospores. Endo- 

 spores were discovered 

 by Pertyini852 (Fig. 

 14). It is necessary 

 to distinguish two 



kinds of endospore- Fig. 14. The endospores of bac- 

 teria (first seen by Perty). 



formation which, how- 

 ever, are connected 

 with one another, 

 through intermediate 

 forms. In bacteria of 

 the first and more comprehensive type, a dark 

 speck appears in the cell-contents after but 

 sometimes without preliminary granulation. 



A. Sporonema ; belongs 

 probably to the swamp bac- 

 teria ; shows Klein's second 

 type of spore formation. 



B. Spirillum undula, per- 

 haps the same as Prazmow- 

 ski's Vibrio rugula. 



