CHARACTERS OF THE BACILLUS 485 



minute oval rods scarcely larger than the influenza bacillus. 

 They stain rather faintly with ordinary stains, and their margin 

 and extremities are often more deeply coloured than the centre, 

 which may appear as an uncoloured spot ; they are Gram- 

 negative and do not form spores. In cultures they present the 

 same characters and are less pleomorphous than the influenza 

 bacillus (Fig. 144). They are specially numerous at the 

 beginning of the disease, and they may be found in large 

 numbers in almost pure culture in the opaque whitish sputum 

 expectorated from the bronchi ; as the disease advances they 

 become scanty, and may 



disappear when the •.^V'^Vi."'- • *■ 



symptoms of the disease , ' i' , ,, "^*l''/ ./'-**►. 



are still prominent. «w* > - >'-''>"" $>% '«. '"•£ '{., 



The bacillus has not JL. ' " ' ,: ^"'> " .,, E\.. ' '. 

 been found in the £ ■ Cg -\ 0. ' M& ^^T . 

 blood, unless as an S b "; '"^ '^i-Wli 

 agonal phenomenon >sfi 3™* , ,'-'-., -L* 3Ef " v J 7 •* 

 (Klimenko). Bordetand % ' -l-.'<t'i i > ' r '' l>/ ". %? £&*$?'■? 

 Gengou succeeded in i'^ ^ *$t£\. jt ^MW«&f-' 

 obtaining pure cultures ,fp\ -..•-- ^ rJ8f> „, •„-, I afttY-JL* 

 on the blood-agar 

 medium described on 

 p. 45, and this was 

 found to be the most 

 suitable of all the media '*>+ v£- > * . ' 



tried. In the first cul- „ 



. .v • Fig. 144. 1 — Film preparation from a twenty- 



tures growth is very four hours' culture of the bacillus of whoop- 

 scanty and may be in- ing-cough. (Bordet-Gengou.) 

 visible, but later it Stained with carbol-fuehsin. xlOOO. 



becomes much more 



abundant, and sub-cultures may also be readily made on 

 ordinary serum-agar media. As compared with that of the 

 influenza bacillus, growth is thicker and less transparent and 

 the margins are more sharply marked off; the presence of 

 haemoglobin, though favouring the growth, is not so essential as 

 in the case of the latter organism. The organism is a strict 

 aerobe, and in the case of cultures in fluid media, e.g., serum 

 bouillon, the tubes ought to be placed in a sloped position, in 

 order to expose a greater surface to the air. Bordet and Gengou 

 completely confirmed the observations mentioned above as to 

 the very frequent, almost constant, presence of influenza-like 

 1 We are indebted to Dr. Bordet for the culture from which this preparation 



was made. 



