160 



THE BLOOD IN RELAPSING FEVER. 



[BOOK i. 



patients suffering from relapsing fever the presence of small organisms, 

 which consisted of slender spiral filaments in a continual state of 

 lively motion. Obermeier further observed that these organisms, which 

 belong to the class of Schizomycetes and which resemble spermatozoa 

 or spirilla, were absent in the period of apyrexia which intervened 

 between the first and second period of fever, and that they reappeared 

 again with the onset of the second period of fever. Obermeier's 

 observations have been verified by all subsequent observers, notably 

 by Weigert, Lebert and Heydenreich 2 . According to these observa- 

 tions it is now clearly made out, that these organisms have exactly 

 the same appearance as the Spirochaeta described by Ehrenberg and 

 found in stagnant waters. They consist of slender spiral filaments 

 O'OOl mm. in diameter, 015 0'2mm. in length; they are homo- 

 geneous in structure ; and they are continually moving, their motion 

 being both rotatory and progressive ; they occur either singly or in large 

 groups, attached to the red and white corpuscles of the blood (fig. 27). 



FIG. 27. THE 'SPIRILLUM' OF RELAPSING FEVER. (Heydenreich.) 

 a, b, c, d shew various conditions of aggregation. At / groups of filaments are 

 to entangle a colourless and several coloured corpuscles. 



They are only found in the blood of patients suffering from 

 lapsing fever, and have not been found in any of the organs of such 

 patients after death. They are found several hours after the onset of 

 the febrile attack, and increase in quantity up to the termination of 

 the first pyrexial period ; they are absent in the interval and reappear 

 again in the blood several hours after the second pyretic period has set 

 in. When examined under the microscope their movements continue 

 for several hours at the ordinary temperature, but a low or a high 

 temperature and several reagents (alkalies, acids, etc.) stop their move- 

 ments at once. 



About their life-history nothing definite is known 1 , nor have 

 observers been able to propagate them in cultivating fluids. In several 

 cases, however, inoculation with a small quantity of blood taken from 

 patients suffering from Relapsing fever has induced the disease. 



1 Klinische und mikroscopische Untersuchungen uber die Parasiten des Ruckfalltyphus, 

 1877. 



2 See an interesting paper "On the life-history of Spirillum," by Patrick Geddes 

 and J. Cossar-Ewart, Proceedings of the Royal Society, 1878, No. 188, p. 481, which 

 treats of the spirillum of stagnant water. 



