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MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 27 



placed to one side of the center. Around the nucleus is a yellowish, granular zone, which in turn 

 is surrounded by a grayish zone, also granular, and which has very irregular edges. Both are 

 finely veined. After several days the surface colonies attain a diameter of 1 mm., and become 

 porcelain white and elevated, with even edges. The deep do not get much larger, but become more 

 dense and whiter, x 80. There is no change seen in the deep colonies. Those on the surface 

 become too deuse to show much structure. They appear as gray disks with regular margins, 

 and near the margins have a finely granular and veined appearance. There is nothing at all 

 distinctive about the colonies. No liquefaction takes place. 



Agar slant. — On the second day a very thin, translucent layer has formed, which extends to 

 the tube wall for the lower half. It is smooth, shining, and has a greenish tint. After some days 

 it is somewhat thicker, but always very thin and translucent. After ten days the agar acquires a 

 faint yellowish-green tint, which becomes brownish after three or four weeks. 



Gelatin .stab. — Growth occurs along the puncture in twenty-four hours. By the third day 

 there has formed a thin white layer on the surface, which has become 4 mm. in diameter by 

 the end of a week. It is white in color, and has irregular, leafy margins. The 

 growth along the puncture has not increased to any extent. Slow liquefaction is 

 observed about this time, and the surface growth sinks slowly. The gelatin below 

 the liquefied portion becomes cloudy after two weeks. At the eud of two weeks the 

 liquefaction is only about 2 mm. deep, and reaches the tube wall. 



Potato. — At the end of twenty-four hours only a widespread moisture can be 

 seen. By the next day it has become like a thin layer of honey. By the fifth day 

 it is brown and dry-, and has a metallic luster. No further change takes place. 



Bouillon. — A slight, diffuse cloudiness is caused by the second day. At the end 

 of a week most of the growth has settled to the bottom, leaving the liquid tolerably 

 clear. 



Gel. stab. 



Rosolic acid. — Becomes slightly darker after two or three days. 



Litmus milk. — Becomes darker by the third day, after which the color is gradually discharged. 

 The reaction is alkaline. At the end of two weeks the milk is a dirty white, while a blue zono is 

 formed on the tube wall at the surface. After four weeks the casein seems to be dissolved, the 

 milk becoming watery and translucent. 



Sugar gelatin, deep stab. — Growth occurs quite deep along the puncture, and a button forms 

 on the surface, with slow liquefaction. No gas is produced. 



Tndol. — Eeaction negative. 



Relation to temperature. — More rapid and abundant at 35° to 36° C. 



Bacillus Geminus Majok. 



Found at a depth of i feet in made soil, which had been paved for several years. 



Character. — Strict aerobe. No growth in atmosphere of hydrogen. 



Morphology. — Straight, thick rods of irregular length, witii rounded ends. Occurs singly, 

 though short chains are occasionally found. The rods show deeply stained points, usually 

 situated near the ends, from one to three in each rod. 



Spores not observed. 



Motility. — Very slight movement. 



Flagella not demonstrated. 



Colonies on gelatin plates. — Colonies appear in twenty hours as minute whitish dots, x 100. 

 Deep are brownish, granular disks, with even edges. Surface are grayish and wavy looking, 

 and have a wavy outline. Many show nuclei. At the end of forty-two hours the deep are still 

 punctiform. Those on the surface are 1 mm. in diameter and have a greenish cast, x 100. Deep 

 unchanged, except that they have become more dense. The surface are grayish, and have an 

 eccentric nucleus and a wavy outline. They are marked by darker lines irregularly distributed, 

 and joining each other, giving the colony a marbled appearance. The colonies are not unlike 

 those of the typhoid bacillus, but are more granular and coarser. The gelatiu becomes somewhat 

 softened after a time, but no distinct liquefaction can be detected. 



