310 J. S. LAWRENCE AND W. W. FORD 



Thermal death point. In one isolation the spores survived 

 one hour steaming in the Arnold sterilizer; and withstood 18 

 pounds pressure in the autoclave but were killed by 19 pounds 

 pressure. In another isolation from soil the spores survived 

 14 pounds pressure in the autoclave but were killed by 16 pounds. 

 They survived one hour steaming in the Arnold. 



^Bacillus simplex Gottheil 1901 



This organism was described by Gottheil (1901) in 1901 as a 

 distinct species. According to Chester it is the same as Bacillus 

 cohaerens of Gottheil. Cultures of both organisms have been 

 received from Krai's Laboratory in Vienna and can easily be 

 differentiated. The present description applies to the Krai 

 culture and to an organism obtained from soil by Dr. Laubach. 

 The species is evidently one of the rare spore-bearing organisms. 



Morphology. In the Krai culture the organisms are large 

 homogeneous rods with rounded ends, measuring usually 0.5625 

 to 0.75 by 3 to 4.5 microns. At times much thicker forms are 

 seen approximating 1.125 micron in thickness while longer forms 

 6 microns in length are not uncommon. The organisms often 

 grow out into long threads or filaments 10 to 12 microns in length, 

 especially on glucose agar. Even in young cultures the homogen- 

 eous rods lose their protoplasm and are converted into peculiar 

 shadow forms. These are made up of a very faintly staining 

 protoplasm in which denser aggregations of cytoplasm appear. 

 Such forms measure 1. '125 to 1.25 by 12 to 15 microns in dimensions. 

 On glucose agar the organisms have the same morphology but 

 may show an abundance of shadow forms. Involution and 

 shadow forms are very abundant in old cultures. In our own 

 isolation the organisms, while somewhat smaller, did not differ 

 appreciably in morphology, measuring 0.5 to 0.5625 by 1.5 to 

 2.5 microns but also showing both the thicker and longer forms 

 seen in the Krai culture and the characteristic shadow and in- 

 volution forms. Long forms were also very common on glucose 

 agar. (Figures 18, 19, 20, and 21.) 



Motility. Actively motile in young cultures. 



Staining properties. Gram-positive. 



