Filaria loa 25 



later than the original, which disclosed only trivial changes in 

 the position and character of the object. One may also infer 

 that in one case at least (Eversbusch) the author became con- 

 vinced of the insufficiency of his evidence, since only a brief 

 preliminary communication has appeared and the extended 

 report which was promised therein has not been published. Sub- 

 sequent authors have not hesitated to pronounce these observa- 

 tions erroneous and to maintain that in fact the authors men- 

 tioned had to do with cases of a persistent hyaloid artery in 

 which this vessel exhibited a peculiar worm-like form, while the 

 supposed twistings of the filaria were only the results of vascular 

 pulsations or of movements in the vitreous humor. The explana- 

 tion accords fully with the original records, as I can distinctly 

 affirm after a careful study of them, and indeed elucidates cer- 

 tain points otherwise inexplicable, such as the statement of Fano 

 (1868) that the head of the worm remained constantly fixed at 

 a given point while the body turned and twisted about. Since I 

 have been unable to trace the references to Chiralt and to Santos- 

 Fernandez, it is impossible to say whether these cases of a filaria 

 in' the vitreous humor are to be explained on the same basis or 

 whether a filaria was actually present. 



Quite recently Nakaizumi (1903) has reported a case of a 

 filaria in the vitreous humor which he regarded as an immature 

 F. loa. This conclusion appears entirely inadmissible, even 

 though one rejects the opposite extreme of interpreting this case 

 like those just discussed as some abnormal structure belonging 

 to the eye itself rather than as a filaria. The history of the case 

 gives no evidence that the patient had ever been in a region 

 where F. loa was endemic and consequently where an infection 

 with this species could have taken place. Furthermore, no evi- 

 dence is adduced to indicate the specific character of the filaria 

 observed. If, then, one grants that the object actually was a 

 worm belonging to the genus Filaria, it is certain that it could 

 not have been F. loa, but was some species indigenous to north- 

 ern Europe, and probably F. conjunctivae or F. equina. The 

 habit of the patient, who is said to have enjoyed half-roasted 

 horse flesh, may indicate an infection with a young F. equina. 

 It is exceedingly unfortunate that the literature of science should 



295 



