Cultivation 543 



granular contents. Sometimes there is a distinct concentric 

 arrangement of the substance composing them. 



Gelatin. In gelatin puncture cultures a delicate white 

 line occurs along the entire path of the wire. When viewed 

 through a lens, this line is seen to consist of aggregated 

 minute colonies. Upon the surface the development is 

 much more marked, so that the growth resembles a nail 

 with a pretty good sized flat head. If the bacilli be 



Fig. 156. Bacillus of chicken-cholera, from the heart's blood of a 

 pigeon. X 1000 (Frankel and Pfeiffer). 



planted upon the surface of obliquely solidified gelatin, a 

 much more pronounced growth takes place, and along the 

 line of inoculation a dry, granular coating is formed. 



Bouillon. The growth in bouillon is accompanied by a 

 slight cloudiness. 



Agar. This growth, like that upon agar-agar and blood- 

 serum, is white, shining, rather luxuriant, and devoid of 

 characteristics. 



Potato. Upon potato no growth occurs except at the 



