GENERAL CHARACTERS OF SPIROCILETES. 67 



aboloidal reflector. The scrapings of tissue can be 

 examined in physiological saline solution or in the fluid 

 exuding from the sore, or a drop of blood can be 

 mounted and sealed so as to exclude the air. The 

 movements of the spirochaetes render them easily 

 visible. It is preferable, however, to add a drop of dis- 

 tilled water to "the fluid containing the organisms, as 

 this causes them to swell somewhat without losing their 

 motility: they are thus more easily recognisable. 



Intra-vitam Staining. Mandelbaum stained living 

 Sp. pallidaz in a hanging drop by adding a loopful of 

 Lceffler's methylene-blue solution along with a loopful 

 of decinormal soda-solution. 



Meirowsky makes a paste of methyl- violet and salt- 

 solution, and rubs it into the (previously cleaned) sur- 

 face of a syphilitic chancre. In the serum which exudes 

 there are found stained specimens of Sp. pallida and Sp. 

 refringens. (Certain more deeply staining dots in. the 

 substance of the organisms he regards as nuclei.) 

 Crystal violet is as efficacious as methyl violet. Sp. 

 dentium may be stained by spreading a drop of fluid 

 containing the organisms on a cover- slip, and placing 

 this face downwards on a drop of concentrated watery 

 solution of neutral red on a warm slide. 



PSEUDO-SPIROCH^TES. 



A vigorous controversy was at one time waged as to 

 the reality of the spirochaetes seen in sections of tissue 

 stained by the silver method, but there is now little 

 doubt as to the genuine nature of these organisms. It 

 may be conceded that the novice might be deceived by 

 appearances presented by nerve fibres, by spirals of 

 fibrin or elastic tissue, or by the edges of cells which 

 take up the silver and present a crinkled appearance 

 (Fig. 54) ; but those who have seen actual spirochaetes 



