METHODS OF EXAMINATION. 491 



bacillus, but very much shorter. These bacilli were some- 

 times found in a practically pure condition. They were 

 actively motile and could be stained by Gram's method. 

 He also obtained pure cultures from various cases and 

 tested their pathogenic effects. They grew well on gelatine 

 at the ordinary temperature producing liquefaction, the 

 growth somewhat resembling that of the cholera spirillum. 

 By injection into cats and guinea-pigs, as well as by feeding 

 them, this organism was found to have distinct pathogenic 

 effects ; these were chiefly confined to the large intestine, 

 haemorrhagic inflammation and ulceration being produced. 



Kruse and Pasquale conclude that so far as our present 

 knowledge of the etiology of dysentery goes, there are several 

 varieties which may be arranged as follows. First, the 

 amoebic or tropical dysentery, having the characters as 

 above described ; second, the various diphtheritic and 

 catarrhal forms without amoebae, possibly produced by 

 bacteria of different kinds, but the nature of which has not 

 been fully investigated; third, the Japanese form of dysentery 

 as investigated by Ogata. 



Methods of Examination. The faeces in a case of 

 suspected dysentery ought to be examined microscopically 

 as soon as possible after being passed, as the amoebae 

 disappear rapidly, especially when the reaction becomes 

 acid. A drop is placed on a slide without the addition of 

 any reagent, a cover-glass is placed over it and the prepara- 

 tion is examined in the ordinary way or on a hot stage, 

 preferably by the latter method, as the movements of the 

 amoebae are more active and it is difficult to recognise them 

 when they are at rest. Dried films are not suitable, as in 

 the preparation of these the amoebae become broken 

 down ; but films may be fixed with corrosive sublimate or 

 other fixative (vide p. 86). In sections of tissue the amoebae 

 may be stained by methylene-blue, by safranin, by haema- 

 toxylin and eosin, etc. 



