BIOLOGIC CHARACTERS 181 



the presence of a capsule when taken from the blood or 

 tissues of an animal, or when taken from cultures in milk 

 or blood-serum? Examine cultures that are several days old, 

 and note whether spores are being formed. Note particularly 

 the position of the spore within the cell. Is the spore of 

 smaller or greater diameter than the cell in which it is 

 forming? Examine cultures that are a week or more old, 

 and note whether the organisms have undergone any definite 

 alterations in form (involution forms), or whether they 

 present evidences of fragmentation or granulation of their 

 protoplasm (degeneration forms). 



BIOLOGIC CHARACTERS. 



Colony-formation. — Observe the character of the colonies 

 formed in gelatin and agar-agar plates. Describe a typical 

 surface colony and a typical deep colony, both as to their 

 macroscopic and microscopic appearance. What is the 

 relative size of the colonies formed on each of these media 

 when they are sufficiently separated from one another to 

 permit unhindered development? Note the color and inter- 

 nal structure of the colonies as well as their relative density. 

 What is the nature of the surface contour and arrangement 

 of the colonies? Note their general character, as to whether 

 they are moist or dry, compact or loosely constructed, 

 sharply circumscribed or spreading over the surface of the 

 medium. Do the gelatin colonies show evidences of lique- 

 faction? 



Agar-slant Inoculations.^ — Observe the nature of the growth 

 on the surface of an agar-agar slant inoculation. Describe 

 the color, texture, and optical characters of the growth. Is 

 the growth confined to the line of inoculation, or has it a 



