CERTAIN GENERA OF THE CLOSTRIDIACEAE 7 



Genus 14. Meyerillus nov. gen. Tj^ie 



species sadowa nov. sp. to be described 



in a future paper. 



BB. Produce less gas from carbohydrates. Heavy Gram-positive or 



Gram-negative rods that form oval spores that are usually 



subterminal. 



Genus 15. Novillus nov. gen. Type spe- 

 cies maligni (Bacillus oedematis maligni 

 II. Novy) as described by Novy. 



Artificial Key to the Genera of the Putrificoideae 



A. Produce an alkaline reaction in meat medium but do not grossly disintegrate 

 the particles of meat. 

 B. Minute Gram-positive rods which form few spores. Clot milk. Weak 

 tissue invaders, or non-pathogenic. 



Genus 16. Seguinillvs nov. gen. Type 



species aerofoetidus (Bacillus aerofoelidus 



Weinberg and Sdguin) as described by 



Weinberg and Sdguin (p. 161). 



BB. Gram-positive rods with oval subterminal or median spores that do 



not greatly distend the sides of the bacilli. Do not ferment milk. 



Typically pathogenic tissue-invaders. 



Genus 17. Reglilhis nov. gen. Type spe- 

 cies progrediens nov. sp. to be described 

 in a future paper. 

 AA. Attack proteins somewhat more energetically than the above and produce 

 a terra cotta coloration of the meat particles and soften and partially 

 disintegrate them. (The terra-cotta color i.s not to be confused with 

 the pink color produced in meat medium by the acid from sugar fermen- 

 tation.) These organisms continue to multiply in meat medium at a 

 moderate rate for months. 

 B. Show no blackening of the meat-particles on prolonged incubation.* 

 Gram-negative or weaklj' Gram-positive rods with oval subterminal 

 or median spores that distend the bacilli. 



Genus 18. Robertsonillus nov. gen. Type 



species primus (Bacillus I. Hempl) as 



described by Hempl. 



BB. Show after approximately two weeks' incubation a blackening of 



some of the meat-particles. Gram-negative rods with spherical 



end-spores. Typically produce a neuro-toxin. 



Genus 19. N icollaierillus nov. gen. Type 

 species tetani (Bacillus ietani NicoUaier) 

 to be described in a future paper. 



* "Incubation" refers to anaerobic incubation at 37°C except in the case of 

 deep agar tubes which are incubated in air at 37°C. Meat medium is pH 7.2 to 

 start with. 



