478 THIRD PART.—BACTERIA OR SCHIZOMPYCETES. 
Anthracis will not germinate, as far as is known, in the temperature of a room 
oscillating about 20°; the minimum is said to be from 35°-37°C., and the 
optimum can scarcely lie much higher. On the other hand dried spores of Bacillus 
Megaterium several days old germinated without exception in a summer temperature 
of 20°-25°C. in 8-10 hours after they were sown. The cardinal point is not yet 
completely established, but the foregoing data suffice to justify the general statements 
in the introduction to the chapter, and also to show that specific differences exist 
in the Bacteria as in other groups, and must be investigated in each case. 
All spores of Bacteria which have been examined resemble those of the Fungi 
described in page 351 in requiring for their germination a supply of proper nutrient 
substances in addition to the water which they absorb; they germinate therefore 
only in nutrient solutions or on a substratum containing water and a nutrient 
substance. Observation has shown hitherto that the food required to induce 
germination is qualitatively the same as that which is necessary for vegetative 
development; at least germination takes place when this food is present, and we do 
not yet know whether it can take place under other conditions. 
Section CXXXV. The general conditions and phenomena of vegetation 
in Bacteria are, as might be expected, analogous with or like those in other plants, 
especially the Fungi (see section XCVII). 
Although comparatively few cases have been carefully examined to determine 
the relation of temperature to vegetation in Bacteria, it would seem that the range 
of temperature is great and the optimum usually high. 
Brefeld! determined the activity of the vegetative process at different tem- 
peratures by observing in specimens that were well supplied with nutriment how 
long a time elapsed before a division took place in a rod. He found that with 
a parity of conditions a rod formed a division every half-hour when the temperature 
of the air was 30°C., every three-quarters of an hour at 25°C., every hour and a-half 
at 18.75°C., and every 4 or 5 hours at 12.5°C., while at a temperature of 6.2°C. 
the vegetative process was extremely slow. The formation of spores required 
about 12 hours at a temperature of 30°C., an entire day at 22.5°C., two days at 
18.75°C., and several days when the temperature was not above 12.2°C.; below 
6°C. no spores were formed. Vegetation continues active, according to Cohn? and 
Prazmowski, at a temperature of 40°-50°C., and is accompanied with energetic 
movement of the rods. 
‘Bacterium Termo’ grows and vegetates according to Eidam* between the 
temperatures of 5.5°C. and 40°C.; its optimum is 30°-35°C. Koch* states of 
the Bacillus of anthrax, that in gelatine cultures its growth and spore-formation 
are finest and most vigorous at a temperature of 20°-25°C. Between 30°C. and 
40°C. its growth and the formation of new spores usually come to an end in 
24 hours; up to 25°C. the time required for this increases till it reaches 35-40 hours. 
Below 25°C. the decrease in the temperature is very marked in the negative sense ; 
at 23°C. 48-50 hours are required for forming the spores, and at 21°C. 72 hours. 
At 18°C. the first spores appear after about 5 days, at 16°C, after 7 days, and the 

1 Schimmelpilze, p. 46. 2 Beitr. z. Biol. II, 271. ® Cohn’s Beitr. z. Biol. I, 3, p. 228. 
* Mittheil. aus d. k. Gesundheitsamte, I, p. 64. 
