1 66 PA THOGENIC BA CTERIA . 



by a narrow interval. Sometimes, instead of pairs of 

 cocci, fours are seen, the group no doubt resulting from 

 the division of a pair. 



The described hemispherical shape is not exactly cor- 

 rect, for a good lens generally shows the approximated 

 surfaces to be somewhat concave rather than flat. The 

 Germans see in the organism a resemblance to their pop- 

 ular biscuit called a "semmel." 



The gonococcus is small, is not motile, like other cocci, 

 is not provided with flagella, and does not have spores. 

 It stains readily with all the aqueous anilin dyes best 

 with rather weak solutions but not by Gram's method. 

 It can be found in the urethral discharges of gonorrhea 

 from the beginning until the end of the disease, though 

 in the later days its numbers may be outweighed by other 

 organisms. The organisms are generally found within 

 the pus-cells (Fig. 53) or attached to the surface of epi- 

 thelial cells, and should always be sought for as diagnostic 

 of gonorrhea, especially as urethritis sometimes is caused 

 by other organisms, as the Bacillus coli communis l and 

 the Staphylococcus pyogenes. 



The cultivation of the gonococcus is not an easy task, 

 but one which requires considerable bacteriologic skill. 

 Wertheim accomplished it by diluting a drop of the pus 

 in a little liquid human blood-serum, then mixing this 

 with an equal part of melted 2 per cent, agar-agar at 40 

 C. , and pouring into Petri dishes. As soon as the media 

 became firm the dishes were stood in the incubator at 

 37 C., and in twenty-four hours the colonies could be 

 observed. Those upon the surface showed a dark centre, 

 around which a delicate granular zone could be made 

 out. 



When one of these colonies is transferred to a tube of 

 human blood-serum or the above mixture obliquely co- 

 agulated, isolated little gray colonies occur ; later these 

 become confluent and produce a delicate smeary layer 



1 Van der Pluyn und Loag : Centralbl. f. Bakt. u. Parasitenk., Bd. xvii., Nos. 

 7, 8, Feb. 28, 1895, p. 233. 



