GENERAL SYSTEMATIC BACTERIOLOGY 451 



and that he considered the species causing typhus and trench fevers distinct. 

 In typhus he claimed that the organism (Rickettsia prowazeki) invaded the epithe- 

 lial cells of the gut wall, while only rarely is this the case with the trench fever 

 organism {R. quintana), and with R. pediculi which is found in normal lice. He 

 also claims that morphological differences are easily discernible if serial sections 

 are cut. He infected a few guinea pigs, but was not able to pass the disease on 

 from pig to pig, nor to infect mice. 



The type species is Rickettsia prowazeki Lima. 

 Rivoltillus. A name proposed by Heller (1922, p. 20) for the twelfth 

 genus of Clostridioideae with the following description: 



Clostridioideae possessing moderately strong saccharolytic powers. Liquefy 

 gelatin but do not produce H2S demonstrable by a lead-acetate-paper test in 

 blood broth. Produce in meat medium gas and a pink coloration which does not 

 rapidly fade. Clot milk. Do not liquefy serum or egg or disintegrate meat par- 

 ticles. Gram-positive rods, usually short, with median, sub-terminal, or ter- 

 minal spores, which usually bulge the sides of the bacillus. Sporangia not often 

 much larger than vegetative rods. In tissue the sporangia may be uneven in 

 their staining reactions, "granulose" being present; orgonts are long, frequently 

 with parallel sides. Usually form chains on the liver of animals. Colonies in 

 deep agar, though they may start as lenticular structures, consist later of a dense 

 center and a wide loose woolly periphery. They vary in size, etc., according to 

 species. Typically highly pathogenic tissue invaders that produce haemolysis 

 ih the animal body. Pathogenic for a wide range of species. 



Type species R. vibrion (the vibrion septique of Pasteur), as defined in a future 

 paper. Robertson (1920) has divided the group into four sub-groups on the basis 

 of the agglutination reaction. 



Robertsonillus. A name proposed by Heller (1922, p. 24) for a 

 genus of the Putrificoideae with the following description: 



Putrificoideae that produce on meat medium a little gas and a terra cotta 

 coloration, multiplying slowly for a long period. A black pigment is absent. 

 Sugars not fermented. Weakly Gram-positive rods with oval spores, usually 

 subterminal, that somewhat distend the bacillus. Two spores are produced. 

 One species, found twice in moulds. Non-pathogenic for guinea-pigs in pure 

 culture. 



Type species R. primus (Bacillus I, Hempl) as described by Hempl. Descrip- 

 tions of bacilli similar to this have not been noted. Proteolytic organisms pro- 

 ducing a terra cotta coloration in meat medium are not uncommon, however. 



Saccharobacillus. A species of organism named Saccharohacillus 

 pastorianus by Van Laer (1889) was found by this author to be the cause 

 of the disease of beer called "turning," in which the beer loses its 

 brilUancy, becomes disagreeable in smell and taste and forms a sedi- 

 ment. According to Henneberg (1909, p. 480) the colonies on wort 



