238 BACTERIOLOGY. 



In the slip stained by the Gram method the same 

 groups of the cocci which grow as threes and fours will 

 be seen, but our lancet-shaped diplococci will now pre- 

 sent an altered appearance — there can now be detected 

 a capsule surrounding them. This capsule is very 

 delicate in structure, and though a frequent accompani- 

 ment is not constant. It can sometimes be demonstrated 

 by the ordinary methods of staining, though the method 

 of Gram is most satisfactory. (Fig. 52.) 



In the third slip, which has been stained by the 

 method given for tubercle bacilli in sputum; if de- 

 colorization has been properly conducted and no con- 

 trast stain has been employed, the field will be color- 

 less or of only a very pale rose color. None of the 

 numerous organisms seen in the first slip can now be 

 detected, but instead there will be seen scattered through 

 the field very delicate stained rods, which present, in 

 most instances, a conspicuous beaded arrangement of 

 their protoplasm — that is, the staining is not homoge- 

 neous, but at tolerably regular intervals along each rod 

 there is seen alternating intervals of light and color. 

 These rods may be found singly, in groups of twos or 

 three, or sometimes in clumps consisting of large num- 

 bers. When in twos or threes it is not uncommon to 

 find them describing an X or a V in their mode of ar- 

 rangement, or again they will be seen lying parallel the 

 one to the other. 



If contrast stains are used, these rods will be detected 

 and recognized by their retaining the original color with 

 which they have been stained, A^fhereas all other bac- 

 teria in the preparation, as well as the tissue-cells which 

 are in the sputum, will take up the contrast color. 

 (Fig. 51.) 



