26 General Bacteriology. 
In cases where vital movement is questionable, remove the cover-glass and place a 
drop of formalin or chloroform in the bottom of the cell; replace the cover-glass, ex- 
amine and note change in character of movement, if any. 
EXERCISE XX. TEST-TUBE CULTURES ILLUSTRATING FORM TYPES. 
a. Make test-tube cultures in bouillon, gelatin, agar and potato of the following 
organisms: 
Micrococcus (any species). 
Sarcina lutea SCHROETER. 
Pseudomonas fluorescens (FLUEGGE) Mic. 
Bacillus mycoides FLUEGGE. 
Microspira Metschnikovi Mic. (or any vibrio). 
Spirillum rubrum v. ESMARCH. 
b. Incubate all cultures, except gelatin, at 28° C. 
EXERCISE XXI. STUDY OF TEST-TUBE CULTURES. 
GENERAL Directions. As soon as growth becomes visible a systematic and careful 
study of the cultures should be made. A detailed list of the points to be noted will be 
found in Chapter III, and should be consulted in writing up the descriptions. The sum- 
mary below will, however, be found useful. 
_ For bouillon cultures note: 1) condition of fluid, 2) character of sediment, 3) pres- 
ence or absence of membrane, and 4) characteristic odor. 
For solid cultures (agar and potato slopes), note: 1) Form of growth, 2) size, 3) 
surface elevation, 4) consistency, 5) color, 6) effect on media, and 7) characteristic odor. 
For gelatin. stab cultures, note: 1) Effect on media, a. non-liquefying, i) line of 
puncture, ii) surface, b. liquefying, i) shape of liquefied area, ii) condition of fluid, iii) 
character of sediment, 2) characteristic odor. 
The study should be continued from day to day as long as changes are noted. Make 
drawings wherever they will be of service in elucidating the descriptions. 
REFERENCES. P. B. C. (Charts by Cheesman.) 
SPECIAL DIRECTIONS. Study and write careful descriptions and make necessary 
drawings of all cultures made. 
EXERCISE XXII. MICROSCOPICAL STUDY OF FORM TYPES. 
a. Make cover-glass preparations from the agar streaks (XX) and stain with an 
aqueous solution of gentian violet or with Loeffler’s methylen blue. 
b. Examine with the oil-immersion objective, write the names of the organisms in’ 
their proper place in the table below. 
Name. Sketch. 
MOGI vs a sacusigane+scarinumasaten 4 Mee ooleibbeee adidas 
Coceaceae (spherical) 
STH ALM ss eos oe bhewh waeentwe hehe apes. Oo Soees. . den temieedle 
DAG de diesen es cinsclsls Soppoae Rae alen GRR ats ook Syste dwedbles 
Bacteriaceae (elongated) 
SNA. es iveetuie arse vec eco 
CUPVECH Se a54 saves concey aiweweeedan 
Spirillaceae (spiral) 
twisted 
