ANAEROBIC VARIETIES. 331 



aerobically upon boiled rabbit's blood, which before the 

 inoculation is again briefly heated to 100° (especially true 

 of Bac. tetani). The latter then forms spores excellently 

 and its virulence increases (v. Hibler). It is also possible 

 to grow anaerobes upon nutrient media containing sulphid 

 of sodium, as stated on page 42. Regarding the behavior 

 of anaerobes in aerobic mixed cultures, see page 43, and 

 Kedrowski (Z. H. xx, 358). 



2. Gelatin is liquefied, and (similarly to Bact. vulgare) 

 fatty acids — from formic to caproic — and, besides, acids 

 with aromatic groups (phenylpropionic acid, hydropara- 

 cumaric acid, and skatol- acetic acid), are produced 

 (Nencki). 



3. Also, without the sugar being present ( ! ), according to 

 Nencki, there arise from albumin: carbonic acid, hydro- 

 gen, H 2 S, mercaptan, marsh-gas, perhaps free nitrogen 

 (Bovet, C. B. viii, 174). The gases have a very foul 

 odor. Phosphoretted hydrogen, which smells like garlic 

 and darkens silver nitrate paper, but not lead paper, in 

 the latter differing from H 2 S, has been found by Marp- 

 mann. 



4. With the presence of sugar there originates a mixture 

 of gases, with less of a putrid but with a sweet, repulsive 

 odor, and consisting mostly of H 2 S and C0 2 . 



5. Spontaneous motion produced by peritrichous fla- 

 gella. 



6. Spores are partly in the middle and partly polar. 

 Attenuated as well as virulent cultures, when grown upon 

 saccharine nutrient media, usually form spores only in the 

 middle or incompletely in the pole, and of an oval form, 

 which may be much elongated. Upon blood and blood- 

 serum in all three varieties the spores are polar and round. 

 In general, sugar and glycerin make the nutrient medium 

 less favorable for spore-formation, and often it very soon 

 fails to occur. This influence is more marked in symptom- 

 atic anthrax and malignant edema than in tetanus. 



7. Regarding their resistance to injurious influences, 

 consult the statements of Sanfelice. According to him, 

 they were not nearly so resistant as the aerobic soil spores, 

 being killed by 100° in live steam in fifteen minutes at 

 most, sometimes also by 80°-90° rather quickly. It re- 



