86 BACTERIOLOGY 



disease in the last six or seven years ; and other parts of Cen- 

 tral Africa have been entirely depopulated. In the earlier 

 stages of the infection, the patients do not show much more 

 than perhaps some enlarged glands in their necks, but later, 

 when the parasite enters the cerebro-spinal fluid, they become 

 emaciated to mere skeletons and suffer excruciating agonies, 

 often going mad before the inevitable fatal termination of their 

 illness. It is hoped that by the isolation of cases, and iby the 

 clearing out of the fly-infested belts of reeds and brushwood 

 around the towns and villages, much may be done to limit tho 

 ravages of this disease ; but it is suspected that the wild game- 

 animals, hitherto carefully preserved, may act as reservoirs of 

 the disease, and these may in the interests of man require to 

 be exterminated before the disease can be finally overcome, 

 if further investigation is found to confirm this suspicion. 



Spirochaetes. There is considerable difficulty and confusion 

 in the classification of organisms of this group and those which 

 morphologically resemble them ; and the proper place and name 

 of many such organisms has not yet been decided. 



Spirochaetes are probably Flagellate Protozoa, though some 

 believe them to be bacteria belonging to the Genus Spirillum. 

 They are long, thin, wavy or spiral, thread-like organisms, 

 usually with pointed ends (see Frontispiece, figs. 19 and 20). 



Spirochaeta pallida (or Treponema or Spironema pallidum) 

 is the cause of Syphilis whether Congenital or Acquired 

 in all its protean forms. The disease is communicated usually, 

 though not exclusively, by direct contagion, and especially by 

 sexual intercourse (see p. 55). The primary lesion, produced 

 by local inoculation, usually shows as an indurated or hard 

 chancre, though this is occasionally not found. From the 

 original sore the disease spreads by lymphatics and later by 

 the blood, with enlargement of lymphatic glands, sore 

 throat, headache, skin-rashes, and invasion of any or all 

 the organs and tissues of the body, the blood-vessels, liver, 

 kidneys, spleen, nervous system, and bones and joints of ten 

 specially suffering. There is no pathological distinction be- 

 tween the so-called primary, secondary, and tertiary stages of 

 the disease, which are purely artificial and retained for clinical 

 convenience. The changes once started, unless promptly treated 

 thoroughly and efficiently by medical means, are progressive 

 and go on indefinitely after infection, often for the remainder 

 of the patient's life, and may kill him in a hundred different 

 ways, by attacking and destroying some vital organ or by causing 

 progressive disease of the blood-vessels and nervous system. 

 They are sometimes rapid, but often extremely chronic, in their 



