carnegie institution of washington publication fig 62 flg 62a streak culture of bacterium stewarti on a 15 agar slant 3 days at 27 c september 1902 the aim on 15 agar slant 8 days at 260 c october 1908 flig 63crystals formed in old nutrient agar culture of bacterium stewarti photographed down upon the nail head of the culture the dark body in the center is the denser growth along the needle track crystals confined to the surface x4 the culture had been at a temperature of about 14 c for many weeks please note that these images are extracted from scanned page rfmg71.jpg from 15 agar old View Photo